system
Given the following post, respond as if you're commenting on Reddit:
human
[DCU] How old is the Flash, mentally?

I want to know how much time has passed, at a rough, ballpark estimate, from his perspective? I don't know whether his speed works by allowing him to travel between space to go great distances or whether he actually runs the whole way. I think I recall a scene where the Flash gets asked what he sees when he runs across a country and he replies that he sees everything and everyone. I have heard that in one battle with zoom he runs across the entire Earth. Not around it, actually across ALL of it. When he runs across the universe in a fraction of a second, how many minutes, hours, years have passed for him? When he uses Cyborg's computer, a machine that can respond to inputs in a fraction of a second, how long must he spend getting those "instant" results? How old is he really?

I hope this question makes sense. Thanks.
gpt
The Speedforce lets most of its users zone out with repetitive tasks. If Flash is running across the country along a highway, he doesn't fully register all of it, only if he's about to run into something. But if he does something that requires attention, he can speed up his brain to match.

On the other hand, people like Quicksilver (from Marvel) experience everything in slow motion and can't zone out to effectively be at the pace of everyone else.