Like Double Back, I had a 36 year career with a major european airline. I was a jet F/O at 20, Captain at 35, compulsorily retired at 55. It was a fantastic and varied career, but I didn't really think ahead to the 'full stop' at 55 years old. Codger sums up exactly how I feel about flying - I did not want to stop doing it. I don't care about the long and difficult hours, interminable problems, problematic passengers, you name it... I actually like the challenge of those situations and the satisfaction of winning against the odds, I really enjoy getting those tons of metal and trusting pax where they want to be.
I did not stop commercial flying at 55, as there are many opportunities out there to enjoy a different culture, language,lifestyle and location, while learning a whole new range of operational skills which are unused or forgotten in the major airlines. The last five years have been richly rewarding in all respects, and to be honest, do you really want to retire at 55 years? I have a half built kit plane to finish, it will be my magic carpet...but...... maybe it can wait a bit while I and others show that 60+ commercial aviating is going to happen.