I don't think the evidence currently available provides an adequate basis for realistic explanations.
Though the first problem (the unconscious factors at work in "explanations") makes its practice very difficult, Keats' "negative capability" would be helpful in the present context.
"I had not a dispute but a disquisition, with Dilke on various subjects; several things dove-tailed in my mind, and at once it struck me what quality went to form a Man of Achievement, especially in Literature, and which Shakespeare possessed so enormously - I mean Negative Capability, that is, when a man is capable of being in uncertainties, mysteries, doubts, without any irritable reaching after fact and reason."
John Keats, letter to George and Thomas Keats, 21 December 1817
Ted