I do not know much about Alan Watts. I gather that he was (after his departure from the Episcopal clergy) a kind of popularizer of Eastern religious traditions to the West. That he would have an affinity for G.K. Chesterton might therefore seem a bit odd — for Chesterton had little positive regard for Eastern religion — but it seems to have nonetheless been the case. In this lecture he describes, quite winsomely, the principal things he learned from Chesterton, with particular attention to the need for wonder, surprise, and humility in a well-lived life.
The date of this lecture is unknown to me, but, considering that Watts died in 1973, I feel quite confident that it must have been given before then. The duration is about 40 minutes.