"(Mem: this isn't quite true, so you needn't believe it. Don't be in such a hurry to belive next time - I'll tell you why. If you set to work to believe everything, you will tire out the believing-muscles of your mind, and then you'll be so weak you won't be able to believe the simplest true things. Only last week a friend of mine set to work to believe Jack-the-giant-killer. He managed to do it, but he was so exhausted by it that when I told him it was raining (which was true) he couldn't believe it, but rushed out into the street without his hat or umbrella, the consequence of which was his hair got seriously damp, and one curl didn't recover its right shape for nearly 2 days. (Mem: some of that is not quite true, I'm afraid.))"
By: Lewis Carroll and Roger Lancelyn Green