Do you think that people that say they are Metal Heads?

Anyways they say they are into metal but don't know who Motorhead is are just retarded? How can you be a Metal Head if you don't know Motorhead? I was just talking to someone earlier and they said I'm a metal head and I like blah blah and I mentioned Motorhead and they were like "Who?" Never heard of them. I walked away. Is it just me? I won't even talk to someone that has never heard of Motorhead.