I'm 63 YO and work out daily. Figure I need to plan for 25 to 30 years, not forever. I plan to retire at age 66, full social security age for me. With just social security and a small pension, and a very Mustachian $1,550/mo in expenses, we will have $1,650/mo in "savings" beyond our basic expenses (including groceries, healthcare, insurance, utilities, gasoline, taxes etc). This is without touching the stash. In fact, this grows to $2,800/mo when DW starts drawing social security just 4 years later.
I may very well draw 8 percent every year I can for a few years, so we can do some of the major travelling we want to do. We want to see Monet's gardens, and the art treasures of Europe, at a leisurely pace. Then, we want to tour the US and Canada, do an Alaskan cruise etc. While we still have our health. At some point, we will just be done and mostly just stay home and enjoy our life, with maybe a cruise or Florida stay to break up the winter monotony. So I'm thinking 8 percent for five or six years, and maybe zero percent thereafter, as $2,800/mo surplus should be more than enough unless we get into hyperinflation. If we become Zimbabwe, not much I'll be able to do but grow my own vegetables and heat my home with free wood from the acres around us.