The best pillows for encouraging sleep were said to be hop pillows. Interestingly, the active ingredients in hop flowers - the sticky, bitter humulins and lupilins - are quite similar to cannabinoids.
But if the bard had spent much of his time stoned, surely we wouldn't have the plays - all we'd have would be reports of some laid-back wastrel telling his contemporaries: "Like, one day I'm going to knock your socks off with these plays. Meanwhile, whose turn is it to get the chocolate..?"