Man that would suck, if everyone was as strong as Superman, then the world would be build accordingly and you would be complety useless and totally handicapped. Maybe i would try to go villian on their ass... somehow, even though that in the comics Superman is atleast a big challenge for even the strongest super villians, so i dont really know what i could do to challenge 7 billion of them.
But think about it, if everyone was ''Superman'' then it would not be super anymore, they would just be ''normal'' and you would be seen as handicapped, just like we see people with muscular dystrophy or paraplegics... just much, much worse, you would be the most handicapped man to have ever lived, you would need help with everything, i mean if everyone could benchpress 500 quadrillion tons and move at the speed of light then every aspect of life would look totally different, would we even use maschines? I mean if Superman choose to use his powers for the building industry he could do the same work in minuts that we could in years.
You would basicly live in a world where everyone moved around at light speed, conqure galaxies in weeks, human society would evolve a million times faster than now, you would be an ant on a planet of 7 billion gods.. You would be forgotten, everything would just flow infront of you without you understanding.