Another item from the archives— this is from Jack Wheaton (1932-2015), my jazz styles and analysis professor when I was at USC in 1988-89.
In some context or other he gave us this list of attitudes/characteristics of professional vs. semi-pro/amateur musicians. I imagine a few of these will be more aspirational than others, for some people. Some are certainly deliberately directed at common jazz student shortcomings as he experienced them in his decades of teaching.
So, you read this then you know how to try to be. I put an arrow by high energy— I think I felt that was a weak spot. I was pretty intense about music, but felt I wasn’t high energy enough.
This list applies to all professions.