One common thing I read with regards to burnout is people saying you might be spending your first 0-12 months post-FIRE just recovering from that. I've always added that as an argument to why being on a potential path to burn out seemed ok, not gonna lie I just romanticized that as spending 0-12 months just working out, doing relaxing things to recover, maybe smoking some weed, so thanks everyone for sharing your stories and adding a more complete picture of what those 0-12 months and more importantly the time leading up to quitting may feel like. I am especially sorry for those that have a mix of burnout and rely on their job for providing to others or for healthcare.
Then again the vocabulary I used was that instead of calling it the "potential path to burnout" I viewed it more as "enduring a job you don't love" for a few more years like a lot of you mention. Though realistically one of the reason I don't love my job (and wouldn't love any job) is because I engage in behaviors that will lead to me burning out like Malcat said. Though in addition to that my job is a 24/7 production facility and my job expectation is that I should answer calls at any time (ends up being, on average, 1x/week at random times, with 1 hr of effort per call), so it can be harder to check out sometimes, but I am learning to.
As a millennial, I don't set super strong boundaries as others have mentioned, but I do not view my job in a way where I feel like I owe them loyalty or where my identity is intertwined, simply a (hopefully short) means to an end. Take that, system...
I've found that few burnt out people actually feel loyalty to their workplace or job, what they feel committed to is a sense of self that is capable of getting shit done under pressure. Its an overwhelming feeling that challenges must be tackled with all you've got, even if "all you've got" includes your health and sanity.
Ironically, the tougher you are, the worse it is.
I used to think my ability to handle anything was a gift. It felt like a superpower. However, the more I learned how to take hits, the more hits I took.
And what happens to a boxer who is tough enough to take hits and keep going? He ends up with the worst brain damage of all of them.
The worse the damage someone endures over time, the nastier the recovery.
By the time I finally started showing the damage, after a solid 20+ years of handling an inhuman amount of shit, my brain was seriously damaged. It was not a pleasant process of just resting while my mind and body politely healed themselves in the background. Do not romanticize decompression. That would be a serious error. It's more like intensive rehab.
Once I finally gave myself a little breathing room, it took a good year, and some extremely uncomfortable therapy to even get to a point where I could begin to understand what just enjoying my life looked like without being in the process of killing myself for the sake of a goal. My husband described me as "the brilliant war time president who is utterly useless in times of peace, so he goes looking for another war".
I'm still not particularly gifted at not overextending myself, and I started my burnout recovery nearly 5 years ago.
I'm tough as nails, and I've learned the hard way that the tougher you are, the tougher the recovery.