I think he figured he wanted to go out on top instead of waiting years later when his heart was no longer into it, his health was bad, or other reasons. He wanted to be remembered being on top of his game in people's minds.
I remember we (me, a few of my cousins) thought we were such hot stuff as young kids on the odd occassion that we were awake way past our bed time and adn got to watch his show. As we grew up, it was not such a big deal to be up that late, but we still watched it.
It just reminds me how much has changed...kids didn't have televisions in their bedrooms like a lot do now, and there really was a sense of "appointment viewing" that hardly exists now with cable, satellite, and TiVo. (people have "their shows" but if you miss it, its on again ina few hours)
