Fear

Fear holds us captive in our own bodies. We are controlled by it. We wish to be let free of it's chains but still they hold us down. But even being caged by fear it is only a figment of the mind. Fear is an irrational feeling that we are tricked by. Fear exists to keep us from doing things that could cause us harm, but when fear comes about because we think about doing something risky, we stop. Because our instinct is that the fear means we are in danger. Which is not always true. It can also be a sign the your doing something right, because you will never do anything great without second thoughts or fear. Fear holds us back but we can't let it be the restraints that keep us from doing amazing things.