I dragged it out until I did 24 years and, generally, I wouldn't change one iota of it except for my last assessment when a plonker gave me a number I couldn't lose in the time remaining. So I left a bit annoyed - but still liking the service life.
Many of my colleagues were shocked at my PVR'ing, (Mrs Rigga too!) and some of them took that as a cue to do the same! In the end, it seems I was a bad influence?
All I really miss now is the social side of things. I get invited to a Mess Ball now and then, and enjoy what remains of the Mess. (Sad, eh!)