The first time you meet Mister Pogo, you’ll say, “Good evening, sir!” because that’s what they will have told you to say. But you’ll be thinking, “This is a very, very, tall and quite scary person, and I find the slugs very offputting.” Probably you won’t be thinking that in words, but in that distilled syllabary that your brain uses to represent ideas in single squirts of neural activity.

The second time you meet Mister Pogo, you’ll say, “Good evening, sir!” because that’s what you remember from last time. And this time you might even mean it, just a little bit, because it will have been several years at the least, and you’ll have learned a lot more about the slugs, and he won’t seem so tall because you’ll be slightly further away, or perhaps he will have shrunk, you can’t be sure. In any case, these aren’t the sorts of things you will be worrying about.

Should you meet Mister Pogo a third time, you’ll probably say, “Good evening, sir!” and this time you really will mean it, because it really will be a good evening, and it really must be, because you know better than anyone, that no-one meets Mister Pogo a fourth time.