I played my first game of Hexakill last week, and it was terrible. I was jungle Shyvana, and we had a duo top plus otherwise standard lanes. All of my lanes lost. Our Ryze went 0 and 6 against the enemy Syndra. The enemy Riven had something like 11 kills in the midgame with over 26 by the end. I was the only one not behind; our bottom lane was losing, but not terribly. We won that game.
Some of that victory comes from the enemy screwing up. I will fully admit that if the enemy had played properly in the midgame, we would have lost. However, even with the enemy's mistakes, we were tens of thousands of gold and several towers behind. How is a comeback like that even possible? Here's how: Stay positive and always look for the silver lining.