- button, button: this was supposedly an attempt by asimov at explicit humour, as though his texts weren't all full of dry wit and bad puns. while i actually think that many of his other texts are more humourous, asimov's clarification that he's going for humour here is really an admission that the text has no point.

- monkey's finger: see previous, although also note that this one is fairly self-referential, right down to the infinite monkey theorem.