So... with the recent revelations I would like to propose a new theory: Tobi is Ichiraku Junior!
Raised and trained by no other then Ichiraku Teuchi. During the third ninja war he opened up a Ramen Shop in the land of rain, supplying all ninjas on the front lines with food (much like the Baratie in One Piece). Things where going well, until some stupid Uchihas and mofos from Kirigakure got into a quarrel inside his shop. Ichiraku Junior tried to calm down the situation, during which he got knocked into the kitchen when shortly afterwards some Suiton: Mizurappa splashed into the deep fryers, causing the boiling oil to erupt and burning half of Ichiraku Juniors face, leaving him permanently disfigured.
Fiercly wounded he drags himself back home, taking a short rest near the Kannabi Bridge, inside a strange cave formed from boulders. There he finds Obito's dead body and uses his skills with the kitchen knife to take out his remaining Sharingan, to replace his own deep fried eye. When he finally arrives in Konoha at his fathers Ramen Shop, begging for help, Ichiraku Teuchi fails to recognize his disfigured son and instead confuses him for some homeless vagabond.
He demands his son to buy some Ramen and eat up before he will listen to him, staying true to the Ichiraku way of a ninja. Ichiraku Junior doesn't have any money though. Coincidentally at the same time Kakashi and Gai where visiting as customers and the enraged Ichiraku Senior ordered them to remove the filthy vagabond from his shop. Obeying the authority of the high ranking Anbu and Root agent, Kakashi and Gai grabed Ichiraku Junior and threw him out of Konohas main gates.
The shock from his own father not recognizing him caused a psychological breakdown and he started to question his own identity, much the same way as Kabuto. It was then when Ichiraku Junior died and the masked man, the nobody who cast down all individuality, was born.
The rest is pretty easy peasy and self-explanatory. He made Zetsu from pasta dough, used the same stuff to fix up some parts of his fried body and then attacked Konoha out of revenge on his father. Minato mistakenly assumed him to be Uchiha Madara, which Ichiraku Junior thought to be pretty cool so he started to act under that name.
Then he set his eyes on Kirigakure and messed with their leader, the Mizukage, to turn the village into what was known as the bloody mist, so that those Mizurappa douchebags would suffer for burning his handsome face. Some time later Zabuza caused shit to break loose and Ichiraku Junior left the village to fuck up the other guys he deemed responsible for his Pizza face: the Uchiha Clan.
So he teamed up with Itachi on the orders of Ichiraku Seniors older brothers Danzou and the Uchiha Clan massacre happened. Satisfied with his accomplishments Ichiraku Junior retired from trolling, but as time flew by, he got more and more bored, until he decided to fuck up the whole world.
From hereon you know the story... the whole Akatsuki, Bijuu, Rikudou Sennin, Forth Ninja War Blabla...
No need to thank me for enlightening you, although I will accept paypal, have a nice day.
Why did Tobi have to be Ramen Guy?????? Makes no sense, how did he cook his noodles to perfection during QB attack??? Tell me that. No way would people not notice a ramen shop as popular as that one not serving perfect noodles 24/7. I don't buy it, the timeline is BULLSH*T.
So Ramen Guy made himself look like a young Obito using his noodle-justu? I mean, yeah, maybe those "scars" are really just noodles, but those noodles should've been crushed under those rocks. Just look at the shadows Kishi himself drew. He just threw logic out the window.
According to the databooks, the noodles on Tobi's face would've dried up by now. Major freaking plothole.
I'll accept that it's Ramen Guy's BODY, but I think someone else is actually controlling the noodles. LOG, most likely.