I admit to being contemplative having marked my tenth anniversary blogging, but I replied:
At 13, I dreamed of being the next great spy novelist. It was early enough that I geared high school and college and grad school toward that goal, and when I was done, I was an adjunct teaching first-year college composition and writing poetry.
Despite all my efforts to direct my talent, I broke into print with a poem. I've placed a hundred more poems since then, and I could spend all I've made from poetry on one slightly indulgent meal at Red Lobster.
I still write poetry because to not do it would only dull my ear for it. I write fiction and nonfiction at the same time because to not write them would only needlessly limit my opportunities. One aspect of writing that will never change is its solitary nature. When one is actually writing, not talking about writing, one does it alone. This lends itself to pursuing one's own idea of success.
For some, success is being name-checked in another author's book. For others, it's self-publishing an opus. For me, success is seeing an idea through to polished work on the page, work I'm proud to submit to an editor, and then move on to my next project.
If your idea of success is money, I may never have enough success for you, but I have had work published that represents me well and expresses what I've had to say as an individual. If all I did for the rest of my life was have work published that represented me well and expressed what I had to say, I might not be wealthy, but I'd be satisfied.