This... is fortuitous I suppose, but my cofounder is actually the one who identified the vertical AND brought the first customer/partner. I was the execution guy who also happened to be a domain expert in a relevant field.
However, to get to this point: this was startup #3 for us together (and monetizeable side project #15~20, by this point in life). Our first startup fizzled out over time as the vertical became efficient (right domain though); our second was poorly executed and run (totally my fault)... but we grew together as a team. And on collective try #3 we learned through our fuckups to not do them again.
I built a platform tool that basically replaced a department of people in this vertical. Add the bizdev cofounder who gets businesses use it and them lock them into long term agreements. Now we have some scale and I get to collect some dividends (low mils) every year that I end up throwing into real estate. My spend is <100k/yr so I figured even if I just dropped everything I could probably count on not worrying about things.
I still work at the company but don't drive the top line revenue -- I mainly tinker around with it because I enjoy algorithm and machine learning problems. (Historically this business is very qualitative and human-powered.)
> How old were you?
I'm 32 and this started two years back.
> What was it specifically that made the cash that ended up in your pocket?
Just the dividends that get dispensed every year. So I get a low mil payout every year -- which is not exactly "never have to work again rich", but the expected value of the business surviving 5-10 years at a minimum is pretty high.
> Do you feel happy in your life?
I'm satisfied but do not intend to be fully happy -- it keeps my edge sharper so my days feel longer, fuller, and with meaning. A lot of my defined purpose (which dispenses happiness) comes from solving problems and adding value friends, so whenever I feel satisfied I just increase the scope of the problem and the definition of those around me.
My biggest life change that set me on this current trajectory was probably when I was 29, where my startup folded, my gf broke up with me, my over-levered investments wiped out, fell into debt, binged on video games and food, and succumbed to depression for a year. Somehow channeling all that hate and self-loathing into recovery gave me a lot of perspective on the absurdities of life and every day I remind myself of this knowledge. I am grateful for every day and am glad to be alive.
However, to get to this point: this was startup #3 for us together (and monetizeable side project #15~20, by this point in life). Our first startup fizzled out over time as the vertical became efficient (right domain though); our second was poorly executed and run (totally my fault)... but we grew together as a team. And on collective try #3 we learned through our fuckups to not do them again.