I'm in my mid-30s and never managed to get ahead in life. I also work in a physically demanding job, and in ten years I won't even be able to do it.
After the time I put aside for work, for sleep, for maintaining a healthy diet, for exercise, for a bit of socialization, for reading or playing games, for cleaning, for studying to advance my 'career', and a little bit of simple relaxation--like posting here--I have about 10 hours a week to write, and another 2 to edit. I average 350 words an hour. This is what I can sustain right now. I recently spiked my production to 35 hours a week to finish the second book of my novel under my stated deadline, and I know I can't sustain that level for more than three weeks without burning out. Would I like to do more? Yes. Can I? No, and I've tried. The result is burnout and depression. The last time I tried to turn myself into a typewriter, I wound up not writing for two years afterwards.
I imagine with time and experience I'll be able to raise my level of effort to 14-16 hours a week without burning out. With this constant pressure I'll eventually have a substantial catalog of complete works which, I hope, can't be ignored. My dire situation isn't the bills due next week, but bills will be coming due in the fullness of time. Some of them are bound to be distressingly medical. I do love writing though. If I didn't I'd be pursuing a more reliable bailout plan, like drawing fetish art.