system
Given the following post, respond as if you're commenting on Reddit:
human
[DC]Since the Flash speeds up his subjective sense of time, all of the time, how many years has Barry Allen actually lived?
gpt
It's hard to say without knowing just how time converts from normal speed to his speeds and how many times he's used his speed (countless). 

BUT when Bart Allen decided to read every book in the library he said he had spent around a year reading it all when it had only been 20 minutes to the other Titans. So I'd assume, relative to himself, Barry Allen has lived for a VERY long time.