Long, long, long ago and very far away, in Manhattan in the 1960s, I knew Robert Downey Sr. as a friend and colleague, and we are still in touch today. At the time, we were all part of what was then euphemistically called the ‘Underground Cinema’, a loose conglomeration of filmmakers and artists who centered around The Filmmakers’ Cooperative and the Filmmakers’ Cinematheque, which moved from location to location, continually offering screenings of decidedly outré films, for something like $2 a…