Although I can not vouch for the following story personally, it came from a friend within the airline concerned who is in a position where you could probably trust it's authenticity and if nothing else it's a good laugh.
Older crew member, took demotion to the RH seat to keep flying long haul routes past 65.
Large destination in the USA and the crew are preparing the aircraft for its longhaul flight homeward except where is the FO? Last seen around Duty Free. Passengers start boarding, where is the FO? Ground crew go searching. Didn't take them long to find him wandering around the terminal looking for the gate. Got a bit lost in the terminal.
I'm all for age and experience in the Flight Deck and some guys/gals could go on forever and should have the right to but what about the one's who don't know when to call it quits? Knowing Grandpa is going to fly me to my desitnation 13 hours away but has issues navigating a terminal is not particularly comforting.