I had not heard the term FITE before, but it probably describes me. I could have hung in there with a high-paying corporate job for another 3-5 years and been good and retired before 50, but I just couldn't do it anymore. It was a good job, a good fit with my skillset, a good company, with good colleagues and...I felt like I was dying a little bit more inside every day. I decided I'd rather commit to working longer in more rewarding work, so I left and went to run a non-profit, taking a 50% pay cut.
It was the best decision I ever made. The work was so rewarding, I felt like I'd found my peeps, I loved my new field, and for the first time, I could be my "real" self at work. After 3 years, I decided I didn't want all of the responsibility of being in charge, and I wanted to be on the front lines doing the work, so I've gone back to grad school, meaning no income from me (DH is still working) for six years, plus a massive outlay of cash for tuition, and I'll earn even less when I'm done than I did at the non-profit. And I'm also happier than I've ever been.
Five years ago, I was obsessed with FIRE, but looking back, it was because I was desperately seeking an escape from my current life and thought early retirement would be that. Once I shifted my goal to building a life worth living RIGHT NOW, and made decisions based on that, my life improved drastically. (Note: We had a solid foundation of savings, were already close to FI, so I felt like I had the freedom and flexibility to take some risks.)
I'm still four years away from getting my degree and have no plans to retire, although part-time work is appealing. If I love new my profession as much as I think I will, I will work for many years, although I will likely taper over time. If I don't love it or am not good at it, I'll work long enough to pay back what I took from the family coffers to pay for school, and then call it quits.