(besides the obvious answer of "Writers have bigger priorities than taking scientific-logic into considering in their story-telling)

Imagine the Flash running from Los Angeles to New York City, 2,788 miles according to google maps. To everyone else, he does this in the blink of an eye (or faster), yet with his perceptions he seems to be moving at "normal" speeds. Let's say he's moving at a relative 70mph (we drive that fast, so his relative perceptions could still perceive everything at that (relative) pace), it would take just under 40 straight hours (in his perception) for him to complete this journey. If he was going to NYC to help with some sort of stress, it would be pretty stressful - thinking about it over & over for that long. The easy answer is that during super-speed the flashes don't have that long of a memory (such as not retaining things learned at super-speed). That to them it never feels like they've been running for more than say, 15 minutes. I'm completely fine with this answer. Like the Speed Force, I'll give it as a freebie.

However, Bart Allen has been stated to be able to retain everything during his super-speed. I would think this implies he would feel that full 40 hours. Over time, I would think this would become maddening. Another example straight from the comics - that doesn't require a thought-experiment or math, is in Teen Titans v3 when he reads an entire library. Can you imagine that? If someone told you, "Ok, start reading and don't stop. You don't have to worry about food/sleep/bathroom but you can't interact with anyone until you're done, even if you wanted to. It'll take over a year".

I would just have to imagine moments like that would eventually be maddening for Bart (especially since it's been shown he's got a short attention span (at least when younger)). Sure, it's just fiction....but this is where my mind goes.

Considering Bart once made the Joker cry during his Impulse days, why do you think he hasn't gone insane already?

I think when he run fast he see everything fast too, he just have fast enough reflex to see it normal. It's like when we drive car, just faster.

I think it's Zoom's power whose power a big pis. It's stated that he doesn't run fast technically, he slow down the time around himself. Now, that would mean he run and see everything at normal speed.

@CitizenBane haha, touche!

@mypasswordis1234 I'm not exactly sure what you're getting at with the first part. In my example of LA to NYC I did mention fast-driving (that if human perceptions allow us to still safely travel at such speeds, that Flash's relative perceptions would allow him to travel at "relative fast" speeds. But even then it would STILL be such a long time from his perspective). Regarding Zoom, I could be wrong, but has he ever been shown to travel long-distance with his powers? If not, that would explain it (he just using it in battle and doesn't have to worry about enduring mind-numbingly long travel), if he has...yea, major plot-hole then, haha (though he's a bit nutty too, so who knows if that would bother him).

@lightsout: It's hard to imagine us a different perception, but it always seemed obvious to me that when Flash run long distance, his reflex is good enough to avoid buildings and such, and maybe not even see blurs, but he still a human and his time-perception is stay okay, I mean he feel the travel fast too. Maybe I don't understand you, or you don't understand me. The car analogy only prove me my point, but I can't express myself more detailed on this.

When Zoom fought against Flash, I remember they crossed at least a city, so anyhow, his plot hole well gaped, lol.

@mypasswordis1234: If flash was traveling just under light speed (just an extreme to exaggerate), his perception of time would HAVE to be different. Because of the laws of relativity. That's why whenever (super) fast-speed is featured in movies/TV everything around the super-speeder seems to be moving slow, because time slows down for the person moving fast. The reason he can see everything at "normal" (either normal guy running, or perhaps as high as "human traveling in a car" level of perception) level is BECAUSE his time-perception is slowed down (and thus, a long-distance run would seem to take forever, at least if your "memory" is working normally).

I'm not sure what you exactly mean by "his time-perception is stay okay", but if you meant that if it literally took him only 1 second to travel 1,000 miles that he only feels it as 1-second, I'm saying that by the laws of physics that is not correct (/not possible).

@lightsout: In Superman: Grounded, Superman asks Flash if he sees people and the things around him as he runs past. Flash replies that he doesn't need to, it's all over in a blur. So he might not have his perceptions accelerated to that level all of the time, idk.

Interesting!
I can't remember where I read it exactly...(Maybe Might Avengers or Avengers Academy) but someone comments on how patient Pietro must actually be.  He's always in fast motion, so imagine him waiting in line to use the ATM machine, or get a cup of coffee....
 
The Flash, however, draws on the Speed Force and this not only changes the speed at which his body can move, but it changes the speed at which the electrical impulses in his body moves as well.  
Normally, electricity flows through wire about five percent slower than the speed of light...
Electrical impulses in the body are a bit slower because the current is generated by ions that have to flood into or out of living cells.  Also, the impulse (which travels the length of a neural cell) must sometimes jump a gap from once cell to the next.  This jump is accomplished by molecules called neuro-transmitters.  It takes time to launch from one cell and land on another...   Still, the over all conduction of electrical signals in the body is very fast but MUCH SLOWER than the speed of light.
 
Logically, if the Speed Force, didn't affect The Flash's neurology, his brain would never be able to think as fast as his arms and legs are moving.  It certainly couldn't take in all the information.    SOOOO... he has to think and perceive in fast motion as well....  Which leads to what you're talking about.   The trip SHOULD seem like it's taking forever, even if it only takes a few seconds.   and... YOUR RIGHT!  So, why doesn't it?!?!   I got nuthin.  Please let me know when you figure it out!

I think that you're assuming that his brain works at the same speed as a normal person...but if he's processing all of that information at a superhuman level then he should be fine...it's the slowing down for everyone else part that would be hard on him

@Timandm For non-Bart my guess is somehow memory is very short term when using the SF (for things done during SF (only because I would imagine it would be bad if it was any short-term memory and Flash could forget battle plans that happened before hand, lol)). For Bart & his idedic memory.....plot hole & I'm questioning all this too much? haha

@danhimself Noooo, I'm already assuming his brain is working a a higher - rate thus his being able to perceive things at a high speed. It's because of moving faster that time slows down, Theory of Relativity (like I was telling mypassword). If his body is physically moving extremely fast he is experiencing time slower (regardless of what any writer says).

@Timandm For non-Bart my guess is somehow memory is very short term when using the SF (for things done during SF (only because I would imagine it would be bad if it was any short-term memory and Flash could forget battle plans that happened before hand, lol)). For Bart & his idedic memory.....plot hole & I'm questioning all this too much? haha

@danhimself Noooo, I'm already assuming his brain is working a a higher - rate thus his being able to perceive things at a high speed. It's because of moving faster that time slows down, Theory of Relativity (like I was telling mypassword). If his body is physically moving extremely fast he is experiencing time slower (regardless of what any writer says).

@Timandm: lol, right? It often just yields disappointment. (Do you have a background in math/science that causes you to "need" explanations? (to some extent))

@Timandm: Damn, color me impressed. Biologist myself. Highschool & on I've always been one to run everything through scientific "checks" (when thinking about them). Takes some of the fun out once & a while, but it keeps me sane, lol.

@Timandm: Yea, and sometimes I think it helps with the escape. That is, if you can imagine it to be more-real, it's a more effective fantasy (not that Superman could be real, but I think you get it, lol).

Well said, lol.

@CitizenBane: Scan?

He can speed up and slow down his perception of things. He has complete control over this. I assume this is the case because superman can do the same thing. When he was eating Pie with Barry in a diner he manually sped up his perception because he was curious to see what it would be like , and the world stood still, but the flash' powers are more complex. When he runs, he sees everything and everyone if he chooses to do so. The same way the Flash can think and see every possible outcome of his actions in the blink of an eye. I believe Bart can do this but not as advanced. They just have better mind and body control, otherwise they really would go insane.

In other comic bart said listening to robin seemed to go on for ever, and the new 52 flash mocked batman saying when he talks it feels like it's in slow motion, but I am guessing that was for comedic effect.