Guybrush Threepwood IS a boy in a carnival with his parents and he loves the pirates ride sooo much that he imagines himself as a wannabe pirate [wannabe because he is not a pirate and he is intelligent enough to realize that]. His brother Chuckie is sent to find him but Guybrush does not want to go back to reality. Thus, he makes up the story of the Ghost Pirate LeChuck. He probably has an infatuation about some girl in the park, probably an attendant at the pirates ride. An attendant because...have you all noticed the fact that Elaine ALWAYS wears pirate clothing? Governors are'nt supposed to wear such clothing, its all flowing gowns for them [Elizabeth in Pirates of the Carribean].
Anyways, as I was saying, then maybe he makes up a damsel in distress story since we all know that that kind of story is what kids see most in fairy tales and stuff. He probably interrupts Elaine in the middle of her work and she thus gets annoyed and then Guybrush succeeds in losing his brother Chuckie [LeChuck and the end of SMI] and then at night, he watches the fireworks in the carnival [Disneyland has fireworks at night as a finale] with Elaine and then she mentions her husband [she is probably married in real life].
Guybrush then probably goes home with his parents and Guybrush regards Chuckie as his brother instead of the Ghost Pirate LeChuck and then they all return to Big Whoop the carnival at a later date. Guybrush probably finds out about the E ticket as a treasure which has untold fun potential and so he wanders off again to find it. Some bully probably takes Guybrush's lunch money or something [Largo LaGrande] and Guybrush finds Elaine at a different section of the park, probably in a Mardi-Gras inspired area. He goes all around the place and ends up in an employee type area where he finds the treasure of Big Whoop, the legendary E-ticket. And then he finds LeChuck and they battle and then he ends up back to reality yadiyadiya!!!!
Most of you have probably heard this or something similar. But...here is the twist:
Guybrush's imagination is so powerful, he makes the Ghost/Zombie pirate LeChuck come to life as a living entity. But, LeChuck only existed inside of Guybrush, until...Chuckie finds Guybrush and they fight and Guuybrush defeats him thus somehow, through a spell, LeChuck enters Chuckie and posseses him. Thus the end of MI2 where we see the glowing eyes!! LeChuck is now in the real realm. [Sort of like what Agent Smith does to get to the Real World in Matrix:Reloaded!!]
Now, this theory makes sense when you take into account what Ron Gilbert [the great and wonderful RON!!!!!] said in the chat transcript found in http://www.scummbar.com and also another interview again found there.
He said in the chat transcript that Guybrush and LeChuck are in one case brothers, and in another case NOT. He also said that Elaine never looked at him like a lover but more like a brother, we can hardly expect an adult attendant to think of a kid like Guybrush in a romantic sense [ick!!!] !! Ron also said in the interview that MI has a lot of funny anachronisms that point to real life; e.g-the vending machine in Stan's Used Ship Emporium, the pump in Phatt Island, the Elvis plates, the large amount of stuff at the end of MI2. He also said that it is all funny but the anachronisms are all part of a larger plot.
Whew!!! Well that was long wasnt it?? I hope i'm right or atleast close to the REAL Secret of Monkey Island plot!!!! All I need now is for Ron Gilbert himself to say "Yes!!! You're right!!!! And for your great theory...I present to you this 'rubber chicken-with-a-pulley-in-the-middle'!!!!"

