I just pulled the FIRE trigger on Friday, and when coworkers asked where I was going next, I said, "Home" or "I'm retiring." I got a couple of those pleasant, rueful "I'm a little jealous" responses.
A couple of times, I offered info about the JL Collins stock series or about MMM, but very cautiously, always opening with, "If you're interested, I can tell you what I did to get here."
I've come to believe that it is personality that determines who can follow the FIRE path, more than intelligence, self-control, income level, etc. Stress makes some people spend money; it makes me want to save or even hoard it. Some people feel anxious or deprived when they can't buy lunch at work; I feel accomplished when I bring my own homemade lunch. Some people are too terrified of math or money to think about them; I find them fascinating. I feel lucky to have a FIRE-appropriate temperament; several of my friends work way harder than I do but can't cope with how those choices would make them feel. We all follow our emotions more than our heads, no matter how we rationalize or frame our choices. There are things that send me into a blind panic that I'd do just about anything to get out of; it's just that math & money aren't among them.
OP, I'm glad you found a place where you can talk about your unsettling experience with your friends. What helps me is remembering that we all make the choices we feel we have to, but for each of us, those choices are different. The path you've taken might not be worth it to or comfortable for your friends, just as theirs wouldn't have been comfortable for you. All you can really do is be there for them.
And -- I was way more like your friends 20 years ago; it took a while for me to get comfortable with the choices that led to FIRE. You never know where life will lead you.