From some movie I forgot the title but one up and coming criminal is seeking advice from an older "mentor" who was well known in the criminal arts. The advice he gets:
"Any job, there is a thousand ways you can screw it up. If you're smart you can think of maybe half of them. You ain't that smart."
When things look bad, and it looks like you’re not gonna make it, you gotta get mean... I mean plum mad dog mean. Cause if you lose your head and give up, you neither live nor win. That’s just the way it is.