~Truth~
He never lied to his Sensei, except when the truth would get his brothers into trouble.
His brother's jealousy took them down the tunnel that day. They ran smack into an angry sewer gator, and it was his skill that saved them. The pressure point Sensei had talked about worked, he was thrilled to find, even on such a formidable enemy. He was proud that he had saved them both, proud of his leadership skill. In the end, though, he didn't tell.
Sensei told him once that if he wanted to lead the team, it was his job to keep it intact. Sensei showed him a small clock, how the gears meshed inside, moving in perfect rhythm and harmony. He showed him the oil used to lubricate the gears, and explained that sand or dirt getting into the works would soon ruin the machinery.
He hadn't understood the lesson. It was his younger brother who would appreciate and understand the mechanical metaphor, but he obediently meditated upon the puzzle. It wasn't until Sensei asked about their day, and he saw the relief in his brother's eyes when he casually didn't mention almost dying, that he understood. Their oil was trust.
A/N: The story of the croc refers to an incident that happened when Raph and Leo were playing "Follow the Leader" in the sewers as youngsters. Raph led Leo down a tunnel where there was a giant gator. It attacked them, but Leo saved them by using a pressure point to knock out the animal. The story is told by Raph in Tales of Leo, in the first season of the 2k3 series.