It is a very inconvenient habit of kittens (Alice had once made the remark) that whatever you say to them, they always purr.
Lewis CarrollWhen I come upon anything-in Logic or in any other hard subject-that entirely puzzles me, I find it a capital plan to talk it over, aloud, even when I am all alone. One can explain things so clearly to one's self! And then, you know, one is so patient with one's self: one never gets irritated at one's own stupidity!
Lewis Carroll