My boss turned 67 in August and just sent his youngest to college last month. He married his second wife when he was in his mid-40s and she was in her mid-30s. The second of their two children was a bit of a surprise. On some level, I think that child has kept him more active than he might have otherwise been, but on another, I think the stress of dealing with a teenager when he might have otherwise been an empty nester has taken a toll on him.