My number one goal was not getting 'A's' - and I proved it. I was a 'C' student. You have to be ready to learn. If you're not interesting in learning it doesn't work. As I grew older and wanted to learn and desperately wanted inside information learning was a lot easier.
I've talked to some drummers who seem to have a very hard time staying in shape on the road including some drummers touring with high-profile acts that don't have to live on fast food every night.
