Marty's obsession with collecting films is very well known in the film industry since the eighties. Just read any better 80ies film book about New Hollywood. He

Marty's obsession with collecting films is very well known in the film industry since the eighties. Just read any better 80ies film book about New Hollywood. He sat hours a day in his basement, and often invited others to watch movies with him. So, not secret at all.