While we have very little records of the life of Jesus before he began his ministry, we have some records from Josephus about contemporary events in Palestine.
The first I’m aware of is in 6AD (or CE if you prefer) as recorded by Josephus in Jewish War 2:117-18 and Antiquities 18.1-10. This is when the son of Herod the Great, named Archelaus was ousted in favor of a new Roman Prefect. Judas the son of Hezekiah started a revolt against the new tax that was created against the people. The revolt was crushed and the people in Galilee must have known about something like that.
The second, recorded by Josephus in Jewish War 2.169-74 and Antiquities 18.55-59, was in 26 AD when Pilate assumed the prefectorship of Judea. He brought in graven images of Caesar to Caesarea, a town on the Western shore of the Sea of Galilee. This time it was a nonviolent protest when the people organized a “sit-in” and said they would rather die than have their laws transgressed. The protest seemed to win out. After 5 days, Pilate took down the standards. Could Jesus of Nazareth been there at this protest? Might he had something to do with the organization of it? He was perhaps in his 20s. He might have known about the history 20 years before when all Judas the son of Hezekiah got was bloody Roman revenge. Does it fit in with his teachings? It could be argued that it does. Did he know about it? It is likely that even if he did not participate in it, something this scandalous was probably known to him.
In Luke Jesus talks about “the Galileans whose blood Pilate had mingled with their sacrifices” to which Jesus asks: “Suppose ye that these Galileans were sinners above all Galileans?” (Luke 13:1-2) Were these the same people that had participated in the peaceful sit-in? Jesus knew about events in Jerusalem as well when he records about “those eighteen, upon whom the tower in Siloam fell” (Luke 13:4).
These events with some imagination we can reasonably tie into a narrative of our own Gospel of the Galileans.