Fear

I must not fear. Fear is the mind-killer. Fear is the little death that brings total obliteration. I will face my fear. I will permit it to pass over me and through me. And when it has gone past I will turn the inner eye to see its path. Where the fear has gone there will be nothing. Only I will remain.
- Bene Gesserit Litany Against Fear

Fear is inadequacy issues.
Fear is walking the path of life and not being able to see your own feet.
Fear is wondering whether you will make a difference in life.

Many would argue you should go through life not being afraid.
I argue you should go through life fearing everything.

If you are afraid, you will galvanize yourself to do things you are afraid of.
If you are afraid, you will talk to that girl you have a crush on, even if you have a snowball's chance in HELL of ever making things work.
If you are afraid, you will speak up to your boss, and tell them JUST what you think of that proposal, and how ineffective it would be, and hey, here is a suggestion to improve it.

Fear is what drives us, fear and that desire to do the things we are afraid of. But as they say, Fear is the Mind Killer, the little death. There is a fine line between fearing the world, yet facing your fears, and letting your fear control and guide your actions.
One is reactionary, the other by will and choice.

Free will, your own actions and thoughts, your own choices are what makes you alive. Those choices define you.

So even if you can't see your feet, walk your path, and every so often, wander off and maybe try a shortcut. You never know where it may take you in the end.