On my seventieth birthday, when I reflected that so many of my friends were dead or dying, it hit me that it was high time I got more work done. Ever since that time, I have done the active, smart thing by increasing my productivity. I'm not on the rocks or shoals yet, but the last few years have been a devastation of illnesses and deaths of many good friends. [Star Trek creator] Gene Roddenberry was a loss that deeply grieved me.

Playboy interview (1996)