I promised my story -- it's not the most exciting, and I'm at the older end of MMM 'early' retirement at 51, but I am SO happy to be free, and I wouldn't be if I hadn't stumbled across the MMM forums around five years ago.
Potted history:
Married for 20 years to a financially coercive man. I had nothing to do with our money. I just knew we never had any despite affluent trappings like kids in private school and a massive house with a sea view. Nothing made sense until we split. He was gambling.
Divorced in my early 40s. Two boys to bring up with only a PT teaching job. I got very frugal very fast, and somewhere along the way, I found Dave Ramsey. For all his many faults, working my way through his baby steps meant I felt secure for the first time ever.
Dave tells you to sell everything that isn't nailed down, and to make more money. I had nothing to sell. I went as close to full-time at work as I could instead, and wrote a book per year in the summer hols for five years. That additional cash really helped, but more importantly writing became my joy. I only wished I could do it full-time, but I thought that would have to wait until retirement. As I earned more, I started piling every spare penny into my mortgage, because that seemed logical. No way would I have invested instead - too much like gambling, it seemed to me!
Then I found MMM and learned about finding your 'number' and applying the 4% rule. Once I totted up my net worth I could see I had a gap. Or did I...? (Spoiler: I didn't. All I needed to do was sell my house and live somewhere cheaper. This would free up equity to supplement my income, if needed, until my pensions kicked in.) I could be free seventeen years earlier than I ever imagined.
SEVENTEEN YEARS EARLY. 
This is where I am lucky. In my divorce, I was awarded a decent chunk of my ex's pension pot, but I also had pensions of my own from my pre-children career, which I assumed were tiny. I learned the powerful influence of time on investments. Wow, those pensions had grown.
I made the jump. I took £6k redundancy, sold my house, moved somewhere cheaper, and started to really enjoy life. I write. I paint. I sketch. I take courses. I read nonsense. At some point it will stop raining and I'll get to know my new area.
I now consider myself skinny or barista FIRE because I choose to keep working, but now I only do what I love. I write a book per quarter, and that nets enough to cover my living expenses. However, if I stopped writing tomorrow, I have enough to live on until I can draw down 4% from my first pension pot in 3.5 years. That's what makes me FI.
I now love investing - what a wild ride 2020 was! I have a S&S Vanguard ISA along with a really well managed pension fund, but I also truly enjoy being frugal. I am another cheap to run veggie!
Up-thread, someone mentioned not wanting to scrimp, and maybe not enjoy life by focussing on FIRE. I promise that having control over your money (which means watching where it goes carefully for at least 4 months IMO) means you never have to scrimp in future. You'll have savings instead to spend on your hearts desire, and sinking funds, so infrequent bills don't surprise you. It's magic!
I never imagined that I'd get to this point. Sometimes I have a wobble (Moving house and leaving everything you know during a pandemic will do that to you!) but I just calculate 4% of my pension fund etc and compare it to my outgoings. Even without my royalties, the numbers work.
Not everyone can, or will want to downsize. I didn't move from the south east with millions in equity. I sold a house for £200k and moved to one that cost £140k. Because I knew my 'number', I believed that was enough to make the jump.
It worked for me, and I think this thread is really valuable because of all the different routes people are taking, for so many different reasons. It's so great to see so much intentionality. I hope you all get to live your own version of FIRE.