I'm going full nerd just for you baby. The SW movies are about a Jedi prophecy that some awesome Jedi would come along and bring "balance to the force". The first 3 movies (2000s) are about Obiwan thinking Anakin is this one that is prophesied about and trying to convince the Jedi of it too. It doesn't work out, all the Jedi are killed. Obiwan sort of sucks at his job. At the end of the third movie (Revenge of the Sith) there are 2 Jedi alive (Yoda, Obiwan) and 2 people with a super super high likelyhood of being seriously Force enabled someday left in the galaxy (newborn Luke and Leia).
There is still this unfulfilled prophesy tho which states that a Jedi will bring balance to the force.
So Yoda goes into exile (his word). Obiwan takes one of the potential Jedi kids to their next of kin on some shitty little planet and spends the next 20 years watching him grow up from afar- waiting too see if he is the one. Bail Organa (Jimmy Smits in the movies) adopts the other lil Jedi and does the same thing on a different planet. As soon as either Skywalker kid showed a gift with the force (or at some point) they were to be taken to Yoda to train them in the ways of the Jedi so the prophesy could be realized. That all went to hell when Leia had to go and join the rebellion, gets caught up in some espionage, gets her Uncle and Aunt killed and winds up thrown in jail. Ultimately she lies to the cops and get her whole planet (and adopted parents) blown up. Teenage girls are the worst.
After the death of Kenobi and the destruction of the death star (1) Ben comes back to Luke as a ghost on Hoth and says what "Get your ass to Dagobah- Yoda is gonna teach you the ways of the force." Now if Yoda is hiding on a planet that hides him from those with the force (yep, thats part of why yoda chose it- Emperor can't sense him there) how could Kenobi know where to send Luke unless this has always been the plan?
tldr,
Answer: The Jedi Prophesy of the Chosen One.