For those taking this thread personally, don't. Obviously no one knows your personal situation and reasons for FIRE (and to a certain extent, no one cares). Pointing out blindspots is helpful, on both the conservative and risk side. I for one have found the discussion interesting and informative from both viewpoints. I think age at FIRE is also a factor. If you are in your 50's you should probably error on the side of YOLO'ing and making the most of the younger years you have left. If you are thinking about FIRE in your 30's and have no idea what your expenses will be over the next 5 decades, then working an extra year or two in order to have more income for the next 50yrs might be a good tradeoff.
Or spending those two years retraining in a high paying, flexible, fun, recession-proof, ageism proof, part time friendly, geographically flexible, remote-work friendly credential for a profession that I can hop in and out of at will and will really enjoy and likely do for free quite a bit along the way.
I retired as the main breadwinner from my first profession at 38. For me, investing in my human capital is INFINITELY more valuable than a slightly padded 'stache.
I like studying and working, if I'm not making money off of it, I do it anyway. So that's by far the best, most fiscally conservative lever I can pull, I'll likely make much more money in my lifetime from my "retirement" work than from my original career. I modeled my retirement after Pete's: figure out profitable shit you love doing. Do that.
If I didn't do this grad school program, I would be doing a different, less lucrative one. So it costs me basically nothing except for a small student loan because the other program would have been free. I will likely do the other program in my 60s.
When looking at FIRE, especially a very early FIRE people forget that although a long timeline is a risk factor, time is also your heaviest lifter when it comes to wealth. So if you retire in your 30s, figure out a fun and enjoyable way to generate money while you are still young and energetic, then suddenly time isn't a risk factor that erodes your probability of success.
Time can be harnessed to dramatically amplify the value of your savings.
So say you have a soul/body destroying corporate job and you save about 1M by your mid 30s. You live on 40K/yr.
You "retire" and need that 'stache to support you forever including an increase in health costs later on.
You could work a few more years and pump that 'stache up to 1.25M and create a negligible difference in your long-term SORR risk.
Or, assuming your professional skills are useless to you (unlikely), you could retrain in an area you enjoy and work casually to generate 20-40K/yr while just keeping yourself busy and engaged in your life.
Maybe your kids are still in school and you have a lot of workday structure in your life anyway, so it fits well.
Maybe you left the corporate world and finally became a carpenter like you had always dreamed (recent other thread discussed this).
Now every single year that you don't withdraw 4%+estimated inflation is a year that your stache grows. It doesn't matter if your income is steady or reliable, just that on average, you your WR works out to be very low.
Now you're facing your mid 50s with a 'stache that's mostly been left to grow for 20 years.
Maybe now you totally quit. Maybe you've learned new and marketable life skills along the way and have new, profitable projects you would like to try.
You already have MUCH more money than you would had you OMY'd a few times and not worked anymore. But let's say you leave the 'stache largely alone for another 15 years, because generating your COL is just so frickin' easy with hobbies that pay.
Your 'stache has been snowballing now for 30 years. What kind of monstrosity of wealth are you heading into your golden years with? What would it look like compared to the OMY option?
Say Pete never touches his 650K 'stache. Assuming 7%, it's worth over 7M by the time he's 65. Much, much more than if he had OMY'd a few years and never used his ample human capital.
For *me* the biggest risk I can take retiring from my brutal career early is to not leverage my human capital or time at all. The value of my skills/skills I can learn, is far, far beyond what I can save in a few years. And the heavy lifting of decades of compound interest on a modest sum is so much more than I can generate in a few years.
Once I wrapped my mind around the fact that I could turn time, the biggest liability of my plan, into an asset, and all I had to do was find a fun way to leverage my human capital??? That's when I understood my specific risk and asset profile.
Money isn't a thing in and of itself, it is a placeholder for time and energy. If I can use my time and energy in ways that make my life better AND make a profit, then I'm essentially double dipping on time because I get both the income AND the 'stache gains. And I'm not blowing my time and energy assets because I took the time to find work that actually adds to my quality of life.
I mean, imagine if I could invest in a degree that got me paid $100+/hr to write on this forum. Wouldn't that be an idiot proof choice?
My two years are INFINITELY better invested in my current education than they would be in two more crushing, disabling, marriage risking years of my former career.
My path is what's best for me, specifically, given my risks and assets. It took me many years of analysis to figure it out. It was NOT my original plan, or my second, or third, or fourth, or fifth. It took a lot of energy and trial and error to figure out.
Know your levers, figure out the best ones for you. Don't get tunnel vision.
Edit: autocorrect typos on my phone