In Star Wars, Luke Skywalker spends a large chunk of The Empire Strikes Back learning from Yoda in the swamps of Dagobah, potentially longer than you might think. However, his training seems to go by relatively quickly, which concerns Yoda immensely. Yoda warns Luke that leaving before completing the full extent of his training will be devastating to his development as a Jedi, but if Luke stays, he dooms his friends to an early demise.
If Luke Skywalker stays on Dagobah and completes his training, he likely does so for several more years. While it isn't confirmed anywhere in Star Wars canon, Luke spends at least one month training with Yoda on Dagobah. The book From a Certain Point of View: The Empire Strikes Back isn't necessarily canon, but in it, Yoda states that Luke has been on Dagobah for "a few weeks." During this time, Yoda gives him a condensed form of Jedi training that equips Luke with as many fundamental skills as possible. Those few weeks in Yoda’s grueling training are crucial for Luke, giving him enough knowledge to complete the rest of his Star Wars training through experience.
Luke Was On Dagobah Longer Than Empire Suggests
The Empire Strikes Back only features a handful of scenes of Luke on Dagobah, making it feel like a briefer storyline than it is. Since Luke spends more time with Yoda than The Empire Strikes Back suggests, the Empire almost finds Luke on Dagobah. Fortunately, they don't, partly because they are too busy trying to run down Han Solo and the gang. Han’s trouble with the Millennium Falcon is another reason why Luke’s escapade on Dagobah seems much shorter. The scenes with the Falcon seem to fly by, from them being chased through the asteroid field to them hiding inside the space slug.
In reality, the Millennium Falcon has to drift through space without a hyperdrive to make it from Hoth to Bespin. The Falcon has roughly two months of supplies on board for its passengers. Given this, it couldn't take longer than two months to make it to Bespin. There is a large chunk of time when nothing significant happens on their voyage. Meanwhile, Luke is likely in Star Wars' Dagobah cave experiencing a vision of Darth Vader. While the Falcon drifts slowly to Bespin, Luke spends weeks attempting to master the way of the Jedi with Yoda.
Luke's Training Was Way Less Than Most Jedi Receive
Because Luke is only on Dagobah for a short period, Yoda is forced to give him less training than a typical Youngling would receive. Luke is also at a disadvantage because of his age. There is a reason that Jedi Younglings are below a certain age when they begin their training in Star Wars, as Luke has to unlearn much of what he has already learned before he can build on his skills as a Jedi. However, Yoda’s experience in the Clone Wars and his centuries of teaching allows him to teach Luke everything he needs in The Empire Strikes Back.