A 7% average return across 50 years is very different from a 7% return year in, year out, because the former fails to account for generational risk. You don't

A 7% average return across 50 years is very different from a 7% return year in, year out, because the former fails to account for generational risk. You don't have the option of just withdrawing $0 on your "down" years. p.s. if you can find a risk free 7% return on 500k, open a retirement planning business, become very wealthy.