There’s an old proverb (or maybe it’s just the title of a Broadway play) that reminds us of the universal truth: “You can’t take it with you.” Though they’re talking about life after death, I believe it applies to your 40s, as well. If you’re a man on the cusp of middle age, there’s a long list of things you should be leaving in the past. I’m talking about everything from scooters that would be mistaken for a child’s to wildly age-inappropriate clothing to the single worst haircut any man can have—especially someone at your dignified station in life. Now,...