He said that there was a point in his life where "I was good at Halo" so I went to look at his stats in Halo 3 and turns out he's always been a far below average player.
Deci tried to shoot Challenger from across the map using a Mauler... a fucking Mauler. And when they played each other again, Deci cried and complained, saying that Challenger "was camping" even though Challenger had complete map control. Deci gave up instead of trying to gain an edge.