The Stuff that Dreams are made...on?

My husband Henry writes poetry (http://henryspoetry.blogspot.com/). Recently he wrote a poem that made a reference to a line from The Tempest: "We are such stuff as dreams are made on." When he read the poem to me, I had a sense that it was not exactly right. Isn't it "stuff as dreams are made of?" He proved his point with Google. Of course he was right. He was in a production of The Tempest when he was a teenager and as a Middle School teacher he has produced several versions of it over the years.

So why was it stuck so clearly in my mind as "of?" I've seen the play a number of times over the years. I can usually rely on my memory for things like that. So I wanted to see why I had it wrong in my head.

First I went to my collection of Sandman comics for the issue that focused on the writing of The Tempest, with William Shakespeare as a character. But of course Neil Gaiman got it right. I closed my eyes to see what came to mind. Very clearly I saw Humphery Bogart in The Maltese Falcon, "the stuff that dreams are made of." He was responding to a question of what the Maltese Falcon was. I googled it and sure enough he said "of" rather than "on." I'm not sure if I should be chagrined or not that I remember a Shakespeare line based on how it was misquoted in a movie!