Why we keep buying Dad ties for Father's Day

Last-minute Father's Day shopping brings out the worst in all of us. Or rather, the worst judgment. At least, when it comes to neckties.Don't fool yourself: That keyboard tie you bought Dad last year -- because Dad loves music, right?-- is languishing in the back of the closet with his tight jeans from the '80s. And yet you just bought him a new one with geometric equations swirling around rhombuses. Because dads love math?