Maybe Jesus had the kind of authority that comes from talking really loudly. In the middle of a discussion, you find one person expressing their point of view louder and louder, apparently assuming that the one who talks loudest has the most authoritative point of view. The weaker their position, the louder they talk. But I find it hard to imagine Jesus in a yelling match. Maybe Jesus pulled rank.
Many people love to drop names of the important people they know.
Maybe Jesus got his authority by referring often to his relationship with God. In fact, I know the Numero Uno, so you'd better pay attention or else. Maybe Jesus flaunted his resume. Many of us try to gain a little authority by adding a few letters after our name which reflects our education and training. Those letters after their names speak of their authority.