You know how when you're dreaming, and in the dream you walk around the street corner, and you trip, and then your real body jumps up like "did I just trip? dang."
Yeah, I hate that.
Or you're rocking on a chair and you slip and you jump awake.
My personal favourite is when I get hit by a car.
For real. Just the littlest of missteps or accidents that make you jump. Hate them.