Familiar Ground

I was just considering retirement options for adventurers and have concluded that certain classes are just worse off than others. 

Wizards and Clerics can pretty much continue doing what they’ve been doing as they get older.  But what about Rogues and Fighters?  Won’t their skills deteriorate?  Arthritis is not exactly conducive to picking locks or swinging a weapon around.

Psions won’t even need their bodies functioning, so they’re even better off I guess.