I didn't get started 'til late. I was in my early 30s when I got my first position. I spent 1/2 of my LE career (29 years - Jan 1, 2007) working outside and 1/2 inside. If I had the ability to do it over again, I would never have left motors. That was the best 10 yrs of my life (I still practice the 'motor-jock walk' on occassion - usually in the confines of our home, long after the wife's asleep <g>)!
I retired once, in Dec 2001. 12 weeks later, I was working again. I have 3 years, 6 months, and 17 days left 'til permanent retirement, but I'm not keeping track.