Yeah I was being a little facetious. But not much. I have heard of her, but don't know any of her music nor her fashion brands. I probably have seen her likeness, but I have no mental image of what she looks like. I couldn't tell you the names of any of her songs or the names of her brands.

I know who Musk is, I know what he does, I know about the companies he founded, I know what he looks like. All I know of Rihanna is that she is a pop star.

Celebrity is very contextual.