No, these memes are widely circulated and are even monetized through sites like knowyourmeme.com. You could mint an NFT of a meme you didn't create, but it won'

No, these memes are widely circulated and are even monetized through sites like knowyourmeme.com. You could mint an NFT of a meme you didn't create, but it won't sell for much, because people will know it's not minted by the creator. In this case these NFTs are only valuable in sofar as their provenance is verified.