Same, well! Apart from only retiring last year - finally!! 68, could have kept working but I thought enough!!2 years retired now, before that, worked every day of my life since joining mob at 15
As for the OP's brother, if he was a tanky. I was at Bovington for over 20 years working alongside the Army!!
Problem I found listening to them. The careers advisors put them on this very tall pedestal telling them they are so employable and any civilian employer will snap them up. Then the reality of it of it is being a fit, lean killing machine isn't top priority for engineering, building trades etc!!
Always remember the first question an employer asked me after leaving the mob!! "And what civilian experience can you bring to the company!! After 24 years there is only one answer!! None!! Its a killer question but you can work round it!! Just be prepared!!