Something which my marketing lecturer said that has stuck with me ever since: If you can get it for free, don't borrow. If you can borrow, don't beg. If you can beg, don't rent. If you can rent, don't buy 2nd hand. If you can buy 2nd hand, don't buy 1st hand.
I am reading a book recently which debunks several things which I had long taken to be the truth. Though the realization of these true "truths" didn't affect me much, a thought struck me, a dilemma in fact... Should I believe in a falsehood because I feel it benefits me? Or should I reject it simply because it's not true? Hmm.... How much honesty is too much? How much rationale is too much? Hmm.... How much thinking is too much?