When I was 17, in my first semester of college, I got my first check for something I had written, a whole $17 (coincidentally). It was an amazing feeling, something I've never forgotten, even though I've worked as a writer for some 20 years since. Selling my first photo (last week) , felt very much the same. There's a sense of validation, a quiet thrill, to know you've created something that doesn't just get admiring comments, but that another person thinks is worth paying for.
I sold my second photo this week (cropped below). I have a tiny portfolio, and figure I've got a couple years of work ahead of me to get it to a decent size, as I must fit this around other things, namely my FT writing/editing career and my PT sojourn in graduate school (for at least the next year or two)!
But for me, just like writing (well, most of the time anyway), taking photos, editing photos, doesn't feel like work. Whether I'm tweaking photos for stock or working on something more artsy, that sense of being fully invested, fully in the moment, makes all the difference.