Sure, there's no lack of things that one can do with money. But would you be substantially happier? That's the issue at hand. Do you look at people with exorbitant wealth and see unlimited happiness? Do they appear to be in a permanent state of contentment and satisfaction?
Win the lottery or sell a company? Invest most of it, and allow yourself a "raise" you can permanently sustain every year.
It will do far more for you than raising your expenditure once, as you get used to it and return to near your baseline happiness very quickly.
> Would love to start a tech-interactive-art museum
I get what you mean, but having enough not to work is the definition of FU money. It means you can just drop your things and leave when the boss demands you something you're not willing to do.
If you want to tie it to a single scenario I'd say it's taken on a meaning more like 'I'll do what I want to you/your business/parking because I don't care about paying to sort it out if I'm sued'. Parking where I 'can't' & paying the 100x fine seems better to me than finding where I 'can' and paying the 1x ticket sort of thing. Not to say everyone's morals would have them act like that, but illustratively.
I had > 1m at one point. It was enough not to work. It wasn't enough to experiment with random things without risk. Couldn't buy a house in NYC,SF,LA,Seattle. Would just have to go back to work. Couldn't start a business for a project that required 10-20 people. Couldn't really start co-working space for 20-40 people at current rent prices without feeling like I'd probably just be throwing away a few hundred k.
What I could do is travel. Could also live anywhere for a few years.
OTOH, if I had F.U. money, I would do those things and more. I might hire people to do them. There are 5 to 10 apps I'd like to see exist. Would be happy to pay some people to make them and make them open source, if I had FU money. Would love to start a tech-interactive-art museum the size of at least most major museums in big cities. Would consider funding startups.
I have one friend, x-coworker, that picked a different path than me and made lots of $$$ (no idea how much). But, they invest in startups. Goal is to invest $1 million a year. They visit startups and pitch events once or twice a month. They also have a personal project. Otherwise they travel with their S.O. and visit their adult kids around the world.