On the last post, bethh commented:

"I'm curious how you decided to set whatever goal it is that you have for retirement - is it salary times x, or spending times 30 years, or what? I feel pretty sure that if I were in your shoes I'd be retired already!" 

This kind of got me thinking about whether I could indeed be retired already. With about $1.2 million in assets and no debt, I already have a lot more money than many people do when they retire. But I'm still under 50, so I have a long window of time that money has to cover. At some point years ago, I had a somewhat arbitrary number of $2 million as my retirement savings goal, which I guess I had calculated would cover what I thought would be my desired retirement lifestyle. I can't remember exactly what math I did at the time-- maybe I should search my own blog archives to help my memory!
Some people use the rule of having at least 25x what your annual spending will be, on the theory that you can safely withdraw about 4% of your savings each year without eating into it too much, since it would hopefully have investment gains of more than 4% each year.
You also have to think about what "retirement" really means-- does it mean you don't work at all? Are you going to want to fill all that spare time with expensive hobbies and travel? Or are you willing to downshift to some other sort of work that will bring in some income, even if it's not much?
I've played around with lots of scenarios in a retirement calculator-- retiring now, retiring later, having a low income now and retiring in a few years, etc. I always felt like I was more or less on track but retiring early never seemed comfortably within reach based on my current lifestyle.
But here's something that I never added to the scenario: Sweetie.
One night when I was noodling around with all this, Sweetie said "does it let you input another person? You know, we're in this together..."
It's not that I didn't think we were in it together, but actually running the numbers this way made a huge difference. Sweetie owns real estate, and has savings, and a small mortgage. After being unemployed for a couple of years, Sweetie got a job that pays a low salary that covers some of our expenses. More importantly, at age 65, Sweetie will get a good old-fashioned defined benefit pension. And someday, Sweetie will most likely inherit a few hundred thousand dollars unless the family circumstances drastically change.
Plug all that in, and boom, we can both retire now.
Of course, this does not make me totally comfortable. We've talked about getting married at some point, but we aren't yet. Our finances are totally separate except for a token joint checking account with $2000 in it. And I just have this independence thing ingrained in me somehow-- the idea of being supported by someone else is just bizarre! But given how miserable I've been at my job, this is now making me think A LOT about quitting.  That may not be "retirement" just yet, but it's pretty amazing to realize that I may have the freedom to just walk away and not worry too much about what my next source of income is. I could try a new career, try doing consulting work, or just step back into a lower level job with way less responsibility. I haven't had more than a 2 week vacation since I was 22, and the idea of just having some time off is very appealing. Once you get this kind of thing in your head, it's hard to stop thinking about it...
So much in the world is uncertain right now-- would it be insane to just walk away from a secure six-figure job??