It seems to me that there is a natural pathway from hard external training ( and hard opinions! ) in our youth leading to soft ( internal) training in our middle years followed by a phase of interest in healing.
I see this reflected all around me so it seems to be not just a martial arts thing – but perhaps more obvious in that arena – for example I have moved from Karate in my twenties to Tai Chi in my forties and am now ( in my seventies) very involved with falls prevention.