I think "enough" is a mentality. For some folks, it takes little to feel like they have "enough". For others, they never have "enough".
An interesting experience for me when I had enough company stock to feel FI and that retirement was a real possibility. Some folks, like me, retired when they could easily support their current lifestyle plus a little extra for travel or upgrade home or whatever.
Other folks had more grandiose ideas. One of my colleagues who probably had 2x what I did, was too busy building his enormous mansion on the lake. I think he had half his net worth on margin to finance that. So he wasn't ready to retire. He didn't like staying home with the kids anyway - so that also motivated him to keep working.
I remember another (more junior) guy at work remarking that it was easy for me to retire because "I had never developed expensive tastes" or something along those lines. In other words, I could retire early, because I was happy with "less". I got the feeling he needed to be able to show off his wealth (whenever he finally achieved it).
I know with certainly that feeling like I had "enough" was definitely part of the motivation to retire early. I wasn't willing to "hold out for more".
Audrey
P.S. Actually, I do have expensive taste. I definitely enjoy top quality things and food, wine, whatever. I just am very happy with small doses which do not break the bank. I am just not into toys or fancy houses or conspicuous consumption. That saves a lot of money!! It kept me out of debt most of my working life, and it made it much easier to reach FI!