When I first came up, the bullpen was pretty much where they put the guys who couldn't start.
The thing that got me over the hump was accepting that I had to do whatever I could to stay in the game.
Later, I could take something off my slider and I could make my fastball sink, so I really had four pitches.
I think today the players are too nice to one another, but that might change with the unbalanced schedule, with teams playing each other more and more. When you face each other that much, with that much at stake, something's bound to happen.