I noticed that too and yk how some of the people he bought recognized the hat whether it be bc of shanks or Roger.

I think there were some theories that it could be joy boys hat. I also heard that it could have originated from the D clan. Those are just some of the ones that I have heard. But yes I noticed that as well I really did not have any theories of my own however.

Joy boy. He must've also been from the cłan of D. But what's confusing is they say Wano has to be opened and also the Noah and poseidon ;all are waiting for the return of Joyboy. Who is this guy, I initially thought it was Luffy

I think Luffy HAT was made from the larger one. And the hat itself isn't the treasur but the treasure is the power it gives. The power to hear the voice of all things. Two out of three people we know had it had a straw hat.

There is the theory that it was joyboys strawhat and joyboy was a giant

I could totally see that. And could maybe explain the huge straw hat we saw.

So he is either from Elbaf or laughtale was inhabited by both man and giant (this is according to a theory that the last island was the one attacked by the celestial dragons waay back then 800 yrs to be specific). Either way, we know very little about him, hopefully we will get more info at the end of Wano arc...

They think that its joyboys straw hat which is ancient weapon uranus and it compels anyone who sees someone wearing the hat to follow/ally with them. However luffy is actually in possession of the ancient weapon and it is his straw hat (hence how multiple characters have noted on his ability to gain allies)

Maaaybe that huge straw hat or Luff's straw hat IS Joyboy? I dunno.