I have been reading a lot about Marcel Duchamp recently, which is fascinating stuff. He seems to have had a wonderful detached attitude which I recognise (I am not claiming to be as talented, intelligent, attractive, or intriguing). He seems to have kept his life to a bare minimum - considering property and belongings as encumbrances - it's possible he saw close relationships that way, too.
Of course, nowadays, when we think we know what 'normal' human beings are (or should be) we have a definition for everyone, so perhaps he had a tendency to Aspergers Syndrome (high functioning autism - one distinguishing characteristic -feeling like an alien on this planet....) Who can tell, certainly not me.
When I first came across Marchand du Sel (salt seller) I was delighted. And he often reminded me of my dad, too, with that enigmatic, knowing smile - and the chess.