Some quotes that make me think so:
"Personally I didn't think my own work was up to my standards . . . I have a tendency to be supercritical of myself."
"Ive always felt somewhat out of place with other kids my own age."
"The biggest problem was I was terrible for commercials - I couldn't smile on cue. Commercials were too phony for me. It was selling a product, and who owns the product? Are they supporting apartheid? I just didn't like the whole thing, even though it helped us pay the rent. How could I tell anybody to drink cranberry juice? I didn't drink it. I didn't believe what I was saying."
"I never wanted the wealthy fantasies of limosines or the pride of arriving at school in nice clothes. I wanted money so we could buy a great piece of land and be self-contained. That impresses me, that really feels good. It feels like something's been accomplished."
"I get offered a lot of [roles]. And sure, you pause when they say on the phone, 'You won't do this for two, well how about three? But after the movie comes out, I think, 'Man, I'm glad I didn't do that.' It's just not worth it. It's all in the script and whether I believe in it."
Btw, he's AMAZING in Dogfight.