ok, so first of all, I have taken a look into all ideals, and get this, no theory upon some accident during time travel that mutates someone. Anyways, so Pokemon Mystery Dungeon, a game most have not heard of, but anyways you are a human...well...were, until you woke up unconscious on a beach, where a pokemon finds you then they say your a pokemon, to which you say you were a human. I will try to not spoil the Explorers of the sky version too much, but that's what I want to start off with. Anyways so, lets start this way, in the game you learn you came from the future to save the past (story is stranger than Sonic '06). Upon your time travel the first time, you experienced "turbulence" as Grovyle told you in his explanation. You developed amnesia and end up on the ground as a pokemon. anyways, my theory is that Celebi's passage of time became unstable due to a human passing through. The human was de-atomized while passing through, causing shock that turns into amnesia. Upon this a force re-atomizes you into a pokemon so you can continue the journey, although you lost your memory. This is an abstract theory, but I believe it is what happened, if anyone has another idea, please speak it.
Umm...yeah tbh, I don't think may people here will actually care about this. I suggest taking it to some pokemon forums imstead. But, good work on the theory Op
If you just play the post-game you will find out this is all wrong...... Nothing is wrong with the Passage of Time. What happened was Darkrai hit the player while traveling through the passage. This caused the player to turn into a pokemon and the amnesia I've played the game through at least 5 times so don't tell me I'm wrong.