I remember the commercial from when it originally aired — which was before anyone ever heard of Dustin Hoffman.
(Okay, anyone outside of the world of Off Broadway theatre, where he was considered a genius.)
In my Hypnotic Advertising seminar, I teach the value of what I call “Anticipatory Surprise”:
The first time you experience the commercial, it’s a surprise. Afterward, each time you hear (or in this case, see) the spot you gleefully anticipate that surprising moment.
I also point out that the enjoyment is not of the surprise itself but rather of the moment immediately before the character reacts.
You’ll see what I mean the second time you watch this.