In ninth grade, Mr. Tackett, an English and Drama teacher and my school's resident hipster, handed me a copy of Waiting for Godot with the instructions: "Read. Now." I started immediately and read during, and with complete disregard for, whatever classes I had that day, and by the time I'd finished the second act, realized something fairly profound about form that is as true for music as for theatre: You have to be careful to get the repeats right. If you get them right, you necessarily go beyond simple reproduction, as the experience of the repeat changes the memory of the original.
The grand audacity of Godot is not that it's a play in which little is said and less happens, but it is a play in two acts in which little is said and less happens, twice.* The repetition here is not exact, but pseudo-repetition, combining the feeling of worn routine with the sense that the repetition occurs in a world in which time has really passed and the world and the actors and audience in it are all a little more worse (but not necessarily wise) for wear, thus nothing can ever be exactly the same. The edgy discomfort and awkward laughter of the audience during the first act takes on an entirely different edge when the formal repetition of the second act invites expectations which are inevitably disappointed. But disappointment is erased, no, transcended, by the joys of variation, whether in major changes (can the blinded Pozzi of Act Two see any less than the sighted Pozzi of Act One?) or in the smallest details.
The game here has everything to do with memory, particularly the tension between the memories of the audience and the fragile, fractured memories of the characters (has the boy come before?) Moreover, the second act is perfectly scaled down in duration from the first, picking up that trick from slapstick or story- and joke-telling, in which a sequence of quasi-repeated actions gets acted out or told in progressively shorter durations (I wouldn't be surprised if Beckett — intuitively — hit on a golden proportion here), scaled to maximize our attentions. The effect is uncanny: even less happens after intermission than before, yet the laughs lose their awkwardness and become relaxed, honest, tender, and sympathetic and the scant bit of hope that closes the act is just enough to leave one half-hoping for a third act, another day, of similar uneventfulness.
* None of my observations here are particularly novel. Wikipedia quotes the critic Vivian Mercier: "a play in which nothing happens, that yet keeps audiences glued to their seats. What's more, since the second act is a subtly different reprise of the first, he has written a play in which nothing happens, twice." (Irish Times, 18 February 1956, p. 6.)