[The Many-worlds interpretation is the] only completely coherent approach to explaining both the contents of quantum mechanics and the appearance of the world.
My father, Hugh Everett, III, author of the Many Worlds Theory, was a quiet man during the eighteen or so years I shared a house with him. Turns out he was depressed over a sad childhood and then being dismissed as a kook, only later — too late — to be recognized as a genius.
The physical "reality" is assumed to be the wave function of the whole universe itself.