The internet is a stage and we are merely players.
While people certainly play characters in real life, the reality filter created by the internet encourages more extreme forms of playacting and a person’s online person is often very different from who they are in real life.
It’s easy to project an idealized version of yourself on the internet. Thanks to photo-editing apps, the ability to craft perfect responses, and simply the tendency to play to an audience of friends and strangers people are often much bolder, cooler, or more put together online than behind the screen.
On the flip side some people who are very polite and straight-laced in their day to day life take to the internet to let their freak flags fly.
Either way that gap between offline and online reality is ripe for comedy and a slew of “me IRL vs. me on the internet” memes about it have popped up.