The average person looks at our captain and probably thinks he's just a lunatic, a meat-hungry youth who's blinded himself to reality, content to throw his life away chasing will-o'-the-wisps.
But that's not Luffy. At least, not all of him. There's something underlying his carefree personality, allowing him to take the most frozen hearts and help them beat anew. Zoro, Usopp, Nami, Chopper, Robin, me... That funny rubber boy took our hardened, bleeding hearts and molded us into a strange little family that would do anything for each other. That's something a total fool could never have done.
It's when his nakama are messed with that you see the dark side of Luffy; the man inside the boy that's been jaded, that's seen the hand that life can deal, and refuses to stand back and just let it happen. That man fights until He's so broken He can barely stand and still finds another reserve of strength to