Quoting someone comfortable in his own skin-
"I yam what I yam, and that's all what I yam."
Specific to the question: Some people paint; or write; or build ships in a bottle. I fly helicopters.
I like a challenge, but I'm not competitive. I don't care if somebody else can tiddle a wink more skillfully than I. How one tiddles the wink is another question, entirely- I'd find that fascinating.
I'll spend hours, days, or months on something I'm interested in learning how to do, or doing better. Chess, motorcycles, philosophy, astral navigation, photography- Average life expectancy of all hobbies other than flying- 6 months of fanatic interest. But flying has been a passion since childhood. The helicopter aspect was accidental- high school, flight school and Viet Nam. Like a lot of kids, I was afraid I'd miss the shooting. There ought to be a law- but I digress.
I've been gainfully employed at various periods in my life, and nearly always missed flying intensely. The only "job" I've ever had that was as fulfilling as flying- operating immense and expensive machines, making bits of other immense and expensive machines. That's done less expensively in third world countries now, or I might still be doing it. The money was pretty good, and it was dirty, loud and computerized- far more satisfying than sales.