Pride hath its fall

There stood, close to an oak tree, a bamboo reed. The oak tree was stout and strong. Its branches spread out in all directions. The reed was thin and supple. It swayed in whatever direction the wind blew. The oak tree said, in a gruff voice, "You are very docile. Why do you dance to the tune of the wind? Stand up, reed, hold your self erect, as I do. Tell the wind that you are not at its command. Show some guts. This world is for the strong." The bamboo reed did not say a word. Silence, it thought, was golden. ^ "Did you not hear me? Why don't you reply?" the oak tree growled. "What can I say? You are strong and sturdy. I am weak. But listen to me. The wind, if it gets really violent, can be very dangerous. When the wind blows with fury, show it respect. Otherwise..." the reed did not complete the sentence. The oak tree thundered, "No wind can do anything to me." The gentle breeze which made the reed swing, overheard the tree's comment. It brushed over the bark of the tree and wafted away.
A little later, after gathering strength, the breeze turned itself into a wild wind. It came back at a terrific speed turning into a storm. The bamboo reed bent almost double. The wind rushed over it. Then it bumped into the oak tree. The tree won't budge. The wind hit it again. This time the shock ran down and weakened its roots. The branches tried to reduce the speed of the wind. The wind pushed them aside with vicious force. In the process, the tree lost its hold. It got uprooted and crashed to the ground. "There goes the strong oak tree. Wish it had listened to me and showed some respect to the wind. But the oak tree was proud. It hadn't learnt one lesson: Pride hath its fall," the reed murmured to itself sadly.

Meaning: Pride makes one think too high of himself, blinds one to the dangers.

Alternatives: Ego is a man's worst enemy. The weak shall inherit the earth.