"In contrast, investing time and energy in your relationship with your spouse and children typically doesn't offer that same immediate sense of achievement. Kids misbehave every day. It's really not until 20 years down the road that you can put your hands on your hips and say, "I raised a good son or a good daughter." You can neglect your relationship with your spouse, and on a day-to-day basis, it doesn't seem as if things are deteriorating. People who are driven to excel have this unconscious propensity to underinvest in their families and overinvest in their careers--even though intimate and loving relationships with their families are the most powerful and enduring source of happiness."