DEAR ABBY: My husband, who is retired, now prefers to talk exclusively to people under 21. He says he is “mentoring” them, though I haven’t seen any indication of this. He says he has no interest in talking to people our age, so when we get together with our friends, who are mostly our age, he says practically nothing. When I asked why, he said he prefers to impart his knowledge to younger people. I have suggested that he volunteer with younger people, but he wasn’t interested — he just wants to hang out with them. I’m not sure what ...