How do you know when you've gotten to fuck you money? Well it depends upon your situation, but in my financial opinion, if you're a married American couple the magic number is around $2,500,000. Why?
Because with $2.5 million you could into perpetuity make 3% on your money (dividends) and never have to draw on the principle. This is the ideal situation. Why is $75,000 ($2.5 million x 3%) an important number though? Well it doesn't need to be that exact and it changes each year, but ideally you wouldn't want that number to be above the 15% tax bracket. As of this year it's actually $74,900 but taxes are a tricky game where everybody's is different. This is theoretical so look at your own situation when implementing this.
If you put $2.5 million into ETF's netting at least 3%, after 1 year they would be classified as ordinary income, which is great because it taxes them at a lower tax bracket. The tax laws changed favorably over 10 years ago when Congress decided to not tax passive income for people who's income was within the 15% or lower tax bracket. If you're married and make under $74,900 this year, you pay no federal income tax!
This is huge! Since you wouldn't have to pay any taxes this is the equivalent of making probably $120,000 of earned income. Put $2,500,000 in investments, have your house paid, and a small emergency fund to cover insurance premiums if needed. You're good to go!