My immediate reaction to 'failure' is to be sad and disappointed. I think that's natural though, and I'm not sure I quite believe anyone who says they don't feel that.

But yes, I do find that it can be motivating. I'm only speaking for myself here - but realising that I have a choice in how I handle it, how I respond to a setback, is pretty liberating. And I think I've just got to the point where there's so much that I could spend time being disappointed about and blaming myself for, but really it wouldn't do me any good, so why bother? I understand that it isn't always a choice though.