Stephanie Coontz: I know people who retire in order to take care of grandchildren. She says you have more time to do things that you weren't able to do when working so hard. You can travel and have all sorts of new opportunities, she says. But let's flip to the downsides - even if it was a good job, work can be hard and stressful,. maybe we should get to recuperate from the grind? "Let's not ignore a really obvious one," writes Coontz.