Koolau
Give me a museum and I'll fill it. (Picasso) Give me a forum ...
I am very close to giving notice and pulling the plug at 37, if I had to give a base WR, it is going to be about 2.5% for my normal spending, but I expect a few years to spike above that, such as for house buying costs (I am not buying in the current bad buy vs rent climate), or a small spike for moving costs/car replacement. I will someday have SS, a small pension, and a likely moderately sizeable inheritance, none of which have much of an effect when considering the buffer I want before retirement, due to the long time horizon.
Work is flexible but I have a new supervisor I like significantly less, a non-work lifestyle I really enjoy, and I simply don't see the need to go too crazy building a buffer for expenses I don't reasonably expect.
I applaude FIRE at 37 but can't quite relate to it. In my case, that would have left too many loose ends (primarily health care). I considered myself to be FI (Financially Independent) when my company vested my pension (albeit, reduced level) AND more importantly, vested their Retiree Health Insurance supplementation. This all happened at age 51. Not too young, but certainly "early" by most definitions.
With THOSE 2 biggies in hand PLUS my "stash" I was good to go - though (told many times) I didn't go for a few years because I was happy doing what I was doing - until I wasn't. YMMV as always.