Re: You'll know it when you see it.
Congratulations, Bob! Your health insurance has solved what seems to be the biggest ER obstacle. I don't have the guts to live without that safety net. Is management trying to buy your silence?
After two years of ER I still take afternoon naps. 30 minutes seems perfect, 45 minutes means I didn't sleep well last night, and two hours means I'm sick. I did two hours a day for three months of ER before I felt "caught up". I'm amazed at the human body's ability to survive years of chronic sleep deprivation, although "survive" should not be confused with "thrive".
Will you be writing for fun (internally motivated) or money (externally)? Will deadlines still apply? Will you do a book tour this time? How will you avoid becoming an editor's worst nightmare?
Traveler, I think the tipping point is "Where's the fun?" coupled with "Do I need the money?" With health insurance we might even have tried ER with as little as 20x savings/expenses. The military slogan is "You know when it's time to go". Although that's a highly individual realization, it's the only correct one. You'll have no doubt when your time comes, whether you're John Galt or Jarhead or even Ted. There's no magic number or time but there's certainly a magical state of mind.
Catalysts include (in no particular order) a life-threatening moment, a significant life experience (like starting a family or attending a funeral), a career hiccup, new workplace management, a windfall, and discovering an ER discussion board.
I'd seen everything but the windfall & the discussion board, and I was happily contemplating vesting the military pension (at 20 years of service). The military's retirement transition program consists of "It'd really embarrass the government if you left the military and ended up homeless, so here's how to get a job". I was complaining to my father the difficulty of finding a job I cared about, when he said "Why do you want to get another job-- will you need the money?" Hmmmm.
So cut your expenses, boost your savings, and wait for the tipping point. You'll know when.
I also haven't had that post-retirement letdown. I've seen it in others (some of whom are back at work) but my days are still too short to do everything I want to...