As David Letterman heads into the victory lap of his TV career, I think back on Brother Theodore, one of my favorite guests during the host’s early great years, when the brilliant tandem Steve O’Donnell and Merrill Markoe were working their magic behind the scenes. Theodore had previously guested on many other talk shows–Merv Griffin gave him the “Brother” moniker because of a collared shirt the performer wore–but it was with Letterman that the stand-up tragedian left his most indelible impression.

If the mad monologist Theodore Gottlieb’s biography was true, he a had enough drama for ten people: a prisoner of the Dachau concentration camp, a chess hustler in Switzerland, a friend of Albert Einstein (who reportedly was his mother’s lover) and a stage performer unlike all others in New York. He passed away at 94 in 2001.