Hey, if I am obsessed enough to try to beat YI with my feet (I am almost done with World 4) and realize that Extra 3 has 21 red coins and the Extra 5 is the only level without a 3 word title, and of course, the Chomp Rock trick in 6-6 (My favorite glitch int the game, and I found it WITHOUT ANY HELP! HAHAHAHA) I SHOULD be able to get your question (maybe, of course, Fifth seems to know way too much about YI as well) but as you said, It'll require some playing most likely... please ask it today though! I want to see it before Fifth answers it!
PS: I thought it was Kuribo's Shoe when I read your answer, but since guessing the same thing you did would be futile, I had to come up with SOMETHING. I still like frostbite's answer though.
Cuando yo me siento aquí, reflexionar lo que aconteció exactamente con mi vida, yo me dí cuenta algo. Algo interesar. ... algo que no era bastante correcto... algo que pareció hacer mi vida incompleta... algo que hizo mí se siente vacía adentro.. ¿Tan, usted sabe lo que hice? Absolutamente nada. Era el mejor desicion de mi vida. Mi vida no bastante correcta vacía.