At this age the person's motor skills slow down, his sight and reaction time can also be affected by age. If a person has sight, hearing, motor skills issues, or reaction issue they shouldn't try to learn to drive at 65. However, there are some people at this age who are sharp, have great motor skills, and their sight hasn't started to deteriorate. This person could easily learn how to drive and make a good driver on the road.
I feel if a person has reached a certain age and they haven't learned to drive by now, then maybe they shouldn't drive at all. In some countries, there are so many people on the road and it would be dangerous for this person to drive. I also think that people after a certain age should really consider if they are safe on the road or not. There are many people who don't care about others and just drive fast because they are always in a hurry. As a person gets older they don't have the skills or the patience to accept this. Their reaction time slows down with age and this is when accidents happen.