This one is for you Stitch. Here's an excerpt from the IHoB:
"What’s my beef with John Mayer, you ask? The first time I ever saw John Mayer, he referred to himself as “a rock star.” This is a major no-no. There are two important criteria involved in order for you to call yourself a rock star:
1. You must actually rock
2. You must be Robert Plant"
Hear, hear, now toss me a beer.