system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do cooked vegetables grow bacteria (and therefore must be refrigerated) but raw vegetables don't?

If I buy a pack of raw bell peppers and tomatoes, I can leave them out of the fridge for a week and they're still ok to eat. When they eventually go bad it's because they rotted, not because there's bacteria on them (I think).

However, we're always told that cooked food, like let's say I fry the peppers and tomatoes, must be refrigerated and if I left that out for a week it wouldn't be safe to eat. Is that true? Why?
gpt
Cooking breaks down the vegetables and exponentially increases the surface area that the bacteria can start working on. 

As an experiment, try chopping up some salad into very fine pieces. They'll go bad by the end of the day while the unchopped ones are still good to eat for at least a day or two.