Memes arent actually from the Internet, only this particular form of text on a picture meme is. And that particular style has historical precursors in actual physical newspapers.

A good way to think of them is a shared in-joke repeated. If you and your friends keep making the same joke, that’s a meme. Yo mama jokes are a meme.

The Wilhelm scream in films is a meme. It’s often used as a joke by sound designers and done so repeatedly by practically everyone in the industry.