When there’s a thread in Cafe Society to discuss “the only band that matters” and I’ve never heard any of their music or known anyone else who has, either.
It could mean you’re really young. We’re talking about The Clash, who recorded in their best-known lineup from 1977-1982.
No, it means I’m really old, and The Clash never mattered to me or anybody in my circle of musician friends, or any other kind, really.
Oh, OK. Wow. 
BTW, calling them TOBTM isn’t sheer hubris on our part (you must have been rolling your eyes); the OP in that thread is quoting Lester Bangs, who first called them that. 