Why are internet memes popular and why isn't it used by the average person?

I can just tell by the way some people type here that they're autistic and has had too much time on their hands that they forget their language is not common slang. Remember when the internet got popular for awhile and people still didn't use them? It's like some people are here have been or are only familiar with what other people have been making up on the internet. It's so corny sounding too that you can tell what kind of person made it.