I do agree with Thomas. I think Buk did maintain a self-confidence in his work that was as much a drive as anything else. I think the line from the Barfly screenplay "I thought I would be discovered after I was dead" was probably pretty applicable through the 1950's and maybe the first part of the the 1960's. I think into the latter half of the 1960's and then for the rest of his life the public validation of his work continued to swell. But I certainly think he was well aware of his artistic merits, long before anyone else took notice. I would even venture to say that that type of self awareness/confidence is at the very root of such a fantastic quote as "Don't Try".