Good analysis. While the premise of FIRE is based on this, it's never been something I could relate to because you have to live such a small life. Most are single or don't have kids. You won't be able to travel, etc. Reducing your living expenses down to $25k/year is not my cup of tea (I have 4 kids!). Also, I prefer to invest for cash flow so that when I do retire early, I won't have to sell off my investments or worry about market crashes. I would rather work a few extra years and retire at 45 with six figures in passive income than try to retire at 30 on less than $500k in the S&P 500. But to each their own!