It’s easy to change a child but hard to keep him from changing back. Instead of thinking of children as lumps of clay for parents to mold, we should think of them as plastic that flexes in response to pressure—and pops back to its original shape once the pressure is released.

Bryan Caplan, Selfish Reasons to Have More Kids: Why Being a Great Parent is Less Work and More Fun Than You Think, New York, 2011, p. 5