DM: guy who doesn't know me fantasizes about me somehow

This happens a lot on these RP-heavy communities--people who don't know me will insist they're fantasizing about me. They don't know what I look like or what I sound like or act like because we've literally never talked before. They're fantasizing about some made up dream girl and then projecting that on to me. Also, they're usually really confused about why women don't find that flattering. 

To be clear: I think it's pretty harmless to have little passing internet crushes, even on people you don't actually know, just don't make it my problem  😅