I've been a fan of Greg's since his days on Ally McBeal. I just went to IMDb to read about him and found this quote of his:

I don't know if I share this with all actors, but acting is hard for me. It's hard for me to have perspective about what I'm doing. I go beyond being self-critical. When we did the pilot for Ally McBeal, I was convinced I was horrible.

It may be hard for him, but he's darn good at it!!