Optimistic and generally good-hearted, he is not as dimwitted as many believe him to be. Knowing the danger ahead, Luffy is willing to risk his life to become King of the Pirates and protect his crew, Luffy is not dumb, he is just extremely simple. His greatest flaw is his impulsiveness. he often lives by instincts luffy is a yandere ,obsessive, over his lovers. He is very controlling, and often times creepy. Luffy is a rubber person, and so he can stretch his body to extreme lengths.