What Am I Riddles

Question: I'll bring out your bulls,
and slow your roll.
I may even come out of your skull.

What am I?

Question: I attach to your hip and I sing all day.
All I want to do is play.

Question: What gets easier to pick up the larger it gets?

Question: Living I do not exist. Dead I am an inspiration. You always doubt me. But never reject me. I am what is given from old to young. Without me people would not learn mistakes. What am I?

Question: Not only a seat, it’s also a head - what is it?