My least favourite aspect of One Piece....

[Pocket-Gog~]

Is Luffy, why is he so stupid? Was he dropped on his head when he was young???

 

[Let's Go Fearless!]

You could at least tag him you coward.
[mention]Fantastische Hure[/mention]

 

[Captain Cadaver]

Luffy is the biggest example of how a Shonen manga shouldn't do a Goku clone as, unlike Goku who was naive to the world and not actually stupid, Luffy has nothing to excuse his lack of knowledge or his recklessness, never learning from his mistakes. It was more tolerable in the early arcs, but OP's character writing acquired what I'd refer to as "Simpson Syndrome" over the years with the main cast being reduced to a collection of hyperbolised traits rather than being well rounded characters. Luffy was probably hit the hardest by this, quickly becoming just the reckless idiot who likes to fight despite most of the arcs from Marineford and onward making it essential that he mature from his failures.

 

[SSJ2]

He was abused as a child by his grandfather. :withheld