1. Uproarious guffaws from the audience while poor Lucky struggles with his imagined net and / or blabbers his desperate way through a litany about man's diminishment
2. A loud-mouthed 'expert' who insists on explaining and interpreting the play to us while it's being performed - helpfully pointing out, for instance, that Vladimir and Estragon don't move even when they say they're going to leave (as if we could't see that for ourselves)
3. The departure of a good 25% of the audience at the end of the first act because the organizers forgot to mention that it was a two act play and people who hadn't read the play left in the intermission thinking it was all over 
that you begin to realise just how accurate and piercing a mirror Beckett's work is, how perfect a reflection of man's fundamental silliness;
that you begin to experience the disconnected, dystopic poetry of his dialogue as a superior and gritty form of realism;
that you begin to recognise your own life for what it is, banal and trivial, an endless variation on an uninspired theme;
that you begin to know that it is only in these brief moments, when we step outside the dance of words and shadows, acknowledge ourselves as ridiculous and unhappy, that we are, for an instant, beautiful.
- We're in no danger of ever thinking any more.
- Then what are we complaining about?