My father was a diver when I grew up. I have vivid memories of him, with a mask, fins, weight belt, and double hose tank set up. He started me snorkeling in the early 60s and I received my NASDS certification in 1974. I used a mask, snorkel, fins, J-valve tank, and a horse collar. I stopped diving in the 80s and I recently decided to start diving again. I purchased gear for my fiancé and four of our children and we are all taking a PADI course, with our open water dive coming up in 2 weeks.
I am 57 now and while the gear has changed and I am new to using a BCD, SMB, computer, second regulator, and improved ascent techniques, I have no problem diving. It is as if I had never taken a break. However, the course is not torture. It is even fun going through instruction with my family. Additionally, I lost my NASDS card years ago and I dont think it can be replaced. So I think I will need a new card to get air and dive now anyway.
Taking the class again is fun and I am glad I chose to take it. I dont see what the big deal is. To each his own, but if you go through the class with your dad, it should be a thoroughly enjoyable and bonding experience.