Obviously what the One Piece is has been one of the most mysterious questions in One Piece for as long as anyone can remember. I thought of a theory for what the One Piece is and I just want to get it out into the world so that maybe someone can tell me if I'm being crazy or forgetting something really important. prepare yourself for an unhealthy amount of yapping.

What we actually know about the One Piece

First I'm going to go over the confirmed facts and hints about what the one piece could be. Firstly (and most obviously) we know for a fact that it is on Laugh Tale and that it was Joy Boy who left it there. Thanks to Whitebeard we know that it is something of great significance and will change the world when it is revealed. we know that some part of the One Piece is in Wano, or at the very least is connected to Wano. Vegapunk also said that the fate in the world would rest in the hands of whoever laid claim to the One Piece. The real kicker though, and the killer of almost every major theory about the One Piece, is that the One Piece is very funny since all of the Roger pirates burst out laughing when they saw it.

What I think the One Piece is

I want to preface this segment by saying that this is not a perfect theory. There are some problems and potential arguments against it and there's a pretty high likelihood that I'm wrong. That being said, I do believe that there is some sound evidence backing this theory up and I believe this is the best idea I can come up with from the information presented thus far. So now that that's out of the way. My theory on the nature of the One Piece is thus. I believe that the One Piece is the story of Joy Boy, whether that be through the form of a Poneglyph or a mural similar to the one on Elbaph, I believe that the One Piece is a chronicle of Joy Boy's adventures and what he did during the Void Century.

The Evidence

the most significant piece of evidence in support of this theory is that when Roger saw The One Piece he described it as a tale full of laughs (hence why he named the final island Laugh Tale), additionally after Roger had seen The One Piece he openly wished that he could have been alive during Joy Boy's era which would be a natural reaction after seeing all the things Joy Boy did in that era. This would also be key information on what happened during the Void Century which would certainly "turn the whole world upside down" as Whitebeard said.

The Problems

I want to very quickly cover some of the potential problems with this theory, I don't think any of these definitively prove the theory wrong but they do make me more cautious about fully investing in it. First of all, is the fact that Vegapunk said that the fate of the world would rest in the hands of whoever found the One Piece, now this could be explained by information we simply don't have yet. For example maybe this chronicle (Poneglyph, Mural, etc) could have some important secret pertaining to the Ancient weapons. The only other major issue I could think of is what Big Mom said about some part of the One Piece being on Wano or at the very least connected to it, my best guess would be that maybe it has something to do with the Kozuki clan's ancient stone-working techniques (the very same techniques used to create the poneglyphs) but again I'm not certain.

The Craziest Part of The Theory (you can ignore this part if you want... but please don't)

This is the part where I might truly go off the rails crazy about this theory but funnily enough, this is the part that I'm most invested in. If this theory is true then I think it would be very interesting from a meta-perspective because that would mean that in a sense, One piece IS the One piece. What I mean by that is that the whole One Piece manga would then be Luffy's One Piece. For us, the real treasure wouldn't be some world-changing revelation. It would be the stories we told, the adventures we shared, and yeah... the friends we made along the way.