One of the great mysteries to me are the Great Debates over Safe Withdrawal Rates (SWR).
I put Safe Withdrawal Rates into Google and it came up with more than 16,000 hits. One wonders how people managed to retire without knowing their "SWR."
Mathematicians love numbers. Fortunately for them, the stock and bond markets spew-out millions of numbers every day which are carefully preserved and available for them to analyze. Unfortunately for us, past performance numbers do not predict future performance.
I retired in June of 1982 at the age of 57. We had about a $1 million dollar portfolio to last us the rest of our lives. I didn't know about safe withdrawal rates (the Trinity Study wasn't published until 1998). We had no computers, Internet, Monte Carlo, or sophisticated calculators. We only knew that we had to be careful to make our money last ($1M at 4% = $40,000/year before tax).
So what happened? We simply withdrew what we needed and kept an eye on our portfolio balance. Most years our balance went up and we spent the money on vacations, luxuries and charity. When our balance went down we tightened our belt and economized.
This is what most people do and it works.
"There seems to be some perverse human characteristic that likes to make easy things difficult."--Warren Buffet