While there have been plenty of very powerful pirates and marines in One Piece who are a little on the younger side, Luffy and the gang have also come up against their fair share of slightly older enemies along their many adventures. In the world of One Piece, many characters don't exactly slow down all that much with age. If anything, the majority of them simply grow stronger the longer they live, especially the villains, who have had plenty of time to build themselves up as legitimately dangerous and formidable foes for Luffy to take on.