Your Father is a wise man. I turn 81 next month and still ride my motorcycle every Saturday with my retired friends. My right knee was injured in the Korean War and they operated on it. It was okay until about 8 years ago and it started bothering me and I could not safely hold my Gold Wing up so I triked it....and away I go...ha ha We are still RVing and I would love a DP but know I would not use it much and NEVER outlive it...
It is hell getting old.....