I read the book ages ago, so don't recall much of it, but get the basic idea. I somewhat agree with the premise, but I'm not exactly an early retiree. At ~60, just now looking to pull the ripcord. Was FI at age 50, but waited for a few reasons:
1) I'm a late starter. Did a lot of crazy adventure stuff and screwing around in my 20's, so needed to hustle hard to catch up financially.
2) Career has been quite a grind, but an exciting one. And since it has been relatively high-income and involved a fair amount of travel, has allowed wife and I to indulge a lot of the experiences a lot of people wait to do in retirement. As a result, my bucket list not very long.
3) Really, my life, career, and business ventures in general have been an adventure, it's been tough at times, but very gratifying. Certainly not boring.
4) NW really took off the past 10 years, like practically tripled, owing to right assets, right place, right time, and some bold but informed risk taking during the recovery from the Great Recession.
I guess that's the other thing, 10 years ago for me would have been still in the shadow of that massive downturn, so would have been difficult to feel secure about the future at that time. And then just as I was about ready, COVID hit and threw another wrench in the works - my peps needed my help and I could not abandon them in the midst of a crisis.
But, all good things must come to an end, and time for that ~20 year stretch to begin. It is indeed scary to think about how short that sounds when I think about how quickly the past 20 years went by. But, like I said, those last 60 years have been an adventure, really don't think I'd change it.