It was easy to take the library for granted—I’d been going there several times a week for seven years—but my brief absence reminded me how much I loved it (thus proving the advice of happiness experts, who advocate periods of deprivation to sharpen pleasures).

Getting rid of those old clothes isn’t easy. After all, there is still that nagging reluctance, that nagging fear that “what if” years down the road you come to regret giving away that blazer with the big shoulder pads and loud pinstripes. This feeling is normal; studies have found that we tend to value things we already own more highly than they a