You will probably find that you will age out physically before you age out mentally. That is my take on it after talking to many folks around the country as I have had the same concern. I started asking the question when I was 55 and I am pushing 70 now. At this point the parts seem to be wearing out faster than they can be repaired or replaced. That being said, my time to park the tt will be when I cannot handle the hitching and other tasks. So far, it is only the wife that keeps her keys in the freezer.