Chuck Palahniuk said this quote

“ By first believing in Santa Claus, then the Easter Bunny, then the Tooth Fairy, Rant Casey was recognizing that those myths are more than pretty stories and traditions to delight children. Or to modify behavior. Each of those three traditions asks a child to believe in the impossible in exchange for a reward. These are stepped-up tests to build a child's faith and imagination. The first test is to believe in a magical person, with toys as the reward. The second test is to trust in a magical animal, with candy as the reward. The last test is the most difficult, with the most abstract reward: To believe, trust in a flying fairy that will leave money. From a man to an animal to a fairy. From toys to candy to money. Thus, interestingly enough, transferring the magic of faith and trust from sparkling fairy-dom to clumsy, tarnished coins. From gossamer wings to nickels... dimes... and quarters. In this way, a child is stepped up to greater feats of imagination and faith as he or she matures. Beginning with Santa in infancy, and ending with the Tooth Fairy as the child acquires adult teeth. Or, plainly put, beginning with all the possibility of childhood, and ending with an absolute trust in the national currency. ”