Success has a hundred parents, and we can become obsessive trying to name all, whether the cultivation of beginner's mind, being helpful to others, effective problem analysis, the embrace of fear, and much more.

All can be helpful -- and you definitely need help to be successful. But there's one aspect that is singular in nature. Every type of success, no matter how mighty or meek, faces one barrier that can turn back the strongest people.

You have to give up something you cherish to move ahead, and that is a sorrowful undertaking.

What you need to give up depends on your psychology, background, environment, wishes, resources, and limitations. But the specific something you need to leave behind will always be difficult for you.

Perhaps you want to get more done in your life and you decide to wake earlier. For many people, that is constitutionally nothing difficult. Others, however luxuriate in the delicious enticement of rolling over for a few more minutes of sleep. To natural early birds, that sounds ridiculous -- you just get up. But if you are someone who loves that feeling, giving up the opportunity to enjoy it is a challenge, just as staying up late to pursue some creative inspiration might be a task for the early riser.

Maybe you're in a difficult relationship. It could be absolutely the wrong one, and yet alike many others you've had. The familiarity becomes part of your sense of self. Or your attachment to getting exactly what you want or an image of the "right" partner might be the problem and not the other person at all.

To master a new skill like a language or playing an instrument requires practice. You give up part of your limited free time to gain that ability. And even when you have it, you will need to continue practice to keep it.

Becoming a successful entrepreneur means bidding adieu to the safety and predictability of a job and taking a big chance on failure. To walk away can seem foolhardy, with voices inside screaming, "Have you gone totally nuts??"

Partings happen all the time, many outside of our control. A loved one dies and that relationship will never be replaced. A neighborhood changes and you no longer feel at home. You switch occupations and miss all the old colleagues and friends. Parting may be sweet sorrow, but it is also pain that never entirely leaves. Why would you want to invite more unhappiness?

But you pay no matter what. Depart and feel a loss of what you had. Stay and feel regret for what never was. If change is a constant, so is the pain of absence.

When a situation is bad, you can tell yourself that staying is dangerous to your physical, intellectual, or emotional wellbeing or that of people close to you. But when you want to explore a new aspect of life, the explanation rings hollow. You are deserting something or someone you cared about.

And yet, you come to a point where you must walk away from comfort and predictability if you are going to do in your life what you deeply want. No matter how easy it may sound to someone else, it isn't, just as what you would find trivial might be heart-wrenching to that critic. Ends are painful and sad, even when they are necessary.

Realize that you will be sorrowful to some degree and you will grieve. Still, go on. There comes a time to put away childish things when we want to grow up to become who we really could be.