Explaining memes to relatives - A cry for help.

[Ughubughughughughughghlug]

I was actually a moment from writing about the Kilroy Was Here 'meme' so you beat me to it. If that doesn't work can also try the old Budweiser Frog commercials. Or hell the Head-On commercial too.

Commercials, since you mention it, work well as an explanation. As long as there has been teevee there has been people autistically repeating commercial slogans like a joke even though it's not a joke (so, that is, a meme).