When they had left, Jubal said to Duke, "Where the hell have you been all day?"
"Thinking."
"Doesn't pay to. Just makes you discontented with what you see around you. Any results?"
"Yes," said Duke, "I've decided that what Mike eats, or doesn't eat, is no business of mine."
"Congratulations. A desire not to butt into other people's business is at least eighty percent of all human 'wisdom… and the other twenty percent isn't very important."
"You butt into other people's business. All the time."
"Who said I was wise? I'm a professional bad example. You can learn a lot by watching me. Or listening to me. Either one."
"Jubal, if I walked up to Mike and offered him a glass of water, do you suppose he would go through that lodge routine?"
"I feel certain that he would. Duke, almost the only human characteristic Mike seems to possess is an overwhelming desire to be liked. But I want to make sure that you know how serious it is to him. Much more serious than getting married. I myself accepted water brotherhood with Mike before I understood it - and I've become more and more deeply entangled with its responsibilities the more I've grokked it. You'll be committing yourself never to lie to him, never to mislead or deceive him in any way, to stick by him come what may - because that is just what he will do with you. Better think about it."
"I have been thinking about it, all day. Jubal, there's something about Mike that makes you want to take care of him."
"I know. You've probably never encountered complete honesty before - I know I hadn't. Innocence. Mike has never tasted the fruit of the Tree of Knowledge of Good and Evil… so we, who have, don't understand what makes him tick. Well, on your own head be it. I hope you never regret it."
"A Stranger in a Strange Land", Robert Heinlein