I understand the distinction you are making, KTC, and I appreciate it. What it boils down to, in my opinion, is this: we are 'something' in our day to day. 9-5 lives. Then we tell ourselves that we are going to sit down and be someone, something different for a few hours a day.
We tell ourselves that we will be one of the creative 'geniuses' that we've looked up to over the years, Hemingway, London, Nabakov, for a few hours, and that takes a certain type of ego-driven will, or chutzpah.
Never mind telling others that we are doing this, because making yourself believe it, and do it, takes a certain amount of convincing, for some of us. For some, it's role-playing, for others, it's simply acting, and for others it might be channeling. Either way, it takes some amount of convincing and inner persuasion.
Some of us aren't even pretending. For some it's simply an act of will propelling us forward to a new reality and higher level in life, that of creative expression. For others it's simply having the courage to finally, 'scratch that creative itch' that won't go away.
By the time others have found out about it, we may be past the point where we feel the need to explain it to ourselves, and we no longer take convincing, it's just the others who need to be convinced at that point.
Those who become published and do receive payment, need only offer that proof up to the 'others' as our badge of sincerity in our 'new' endeavor.