Who is Matthew?

A depressed alien in the shape of a man ends up in an unusual psychiatric hospital on Earth. Conversations with a female psychotherapist reveal the details of his extraterrestrial life. At the same time, the hero has two more doppelgängers, one of which is a charismatic artist, the second is a schizophrenic. The woman realizes that the words don't matter, what she needs is to understand what's not being said, she needs to remember something. The viewer accepts this - the words are unimportant.