Unlike cats, humans have three lives:
In order to become successful, you must be able to balance each of them. If you find yourself working 80 hour weeks in order to be successful with your business life, your personal and family lives suffer. If you forego your work in order to focus all of your energy on your family, your business and personal (health, well-being) lives will suffer. If you suffer from depression or other health concerns, your business and family lives take the brunt.
I'm not saying anything groundbreaking here. There are times when work needs to come before family. There are times when family needs to be lifted above every other responsibility you have. And sometimes, you need to focus on yourself before the other two.
When each of your lives is in balance...when each is a source of strength for you as opposed to a stress-inducing drain...you will be successful.