This is in part due to the fact that people who have children differ, on average, from those who do not have children in ways that are related to happiness, such as in their marital status, age, and income.
If you're able to spend less time in the office by working remotely or having flexible hours, you should be able to be productive in both your personal and professional life.
It doesn't matter your age, how much money you have in your bank account, your marital status or what you do for a living, we all want to be more successful in our lives.