Not that I'm find fault (after all, *I* am a 30 year old contemplating FIRE at 40
) but how many careers have you had at age 30? Can I ask how many years you've had in the full-time work force?
Paper boy at 12 (kept the paper route until 19)
Bag boy at 15
Wal-mart employee at 16
First contract programming job at 16
Student job as a programmer for the college at 17
Co-op and internship at 19 and 20 (kept the student programming job too, worked remote)
First full-time job as a contractor at 21. Helped with internal tech groups, mentoring junior contractors (most of who were older than me), leading other initiatives, etc
Enterprise architect at a Fortune 100 company at 22... Made it there until I was 26. That was probably the biggest growth job for me. Having to tell someone twice your age and higher up on the totem pole that there was no way in hell he was going to waste $10mm on something just because he wanted a new tech toy was an interesting situation.
That entire job was toxic, but I probably didn't realize how bad it was at the time. When I think back to my most memorable moments there they include things like making another man cry and getting in a yelling match with someone else at 2 am because he was being less than cooperative with helping to launch the new project (those incidents were two years apart). In the middle of another 110+ hour week, when the only time I saw my wife was for half an hour over dinner (she worked at the same company so she'd go get chinese for us to eat together), I started having severe chest pains. I figured it was just stress and would go away... I finally went to the ER when my boss and one of my coworkers told me they were taking me if I didn't go on my own. An EKG confirmed that it was just stress and not a stroke, but that helped confirm that it was time to dial it back.
I'm an architect at another company now. I've been there for four years and I have a completely different outlook on life and especially on my career. My view really started to change along the way at the prior employer and it's just solidified here. Politics and infighting are something to be studied and enjoyed without partaking in now. I'm far enough down in the org that I don't need to participate. I've returned to my love of history and anthropology (I was going to be a history professor until I realized my odds of landing that were slim) and started to just get more mellow about everything going on.
That's my story and I'm sticking to it.