Have you noticed we tend to become more ourselves as we grow older? I call it The Calcifying Effect. A friend says, “Our veneer wears thin and we can’t hide our true selves anymore.” Those impatient, glass-half-empty personalities become grouchier after they turn 50 (then 60, 70 … ), and positive-minded people become annoyingly sunny. Either way, we’re all more difficult to live with. I know it’s happening to me, too. An ol’ misery-guts guy I know has always fumed at people who chat with the cashier, holding up the line. But he never said anything to them; you’d never …