In the world of One Piece, few things are more powerful than an individual with a clearly defined goal. Throughout its many narrative arcs, the series repeatedly demonstrates this phenomenon, beginning in its very first episode when Monkey D. Luffy defeats Alvida and loudly proclaims that he will be the next King of the Pirates. As Luffy adds talented individuals to his crew, each new member is pursuing a specific objective that fuels their ambition. As a result, One Piece's protagonist surrounds himself with a group of dreamers who each hope to accomplish something truly special.
Source：https://www.cbr.com/luffys-dream-one-piece-anime-best-part/
