Earlier quoted context omitted.
I just "won" my endgame :-) I recently retired after working 29 years in software development. I was always very well paid but a notch below the FAANG-level. I always focused relentlessly on achieving financial independence by saving and investing as much as I could using Boglehead techniques. I can now do whatever I want.
Did you start at 21 ? If yes, do you regret not enjoying your 20s and keeping it for your 50s when you're older.
I got a PhD so I started a bit late but I do not regret spending my 20s as a grad student. At least when I started working, a PhD came in useful. I should note that this was a long time ago so my advice may be less relevant today. In general, my advice is to save as much as you can early in your career. Thanks to the power of compounding, $1000 saved in your twenties is worth a lot more than $1000 in your forties.