He may be the Fastest Man Alive, but Barry Allen (Ezra Miller) still has a lot to learn, especially since he's just starting out. As the youngest member of the Justice League, it would make sense for someone as inexperienced as Barry to look to his colleagues for a mentor/mentee relationship, considering he's working alongside the World's Greatest Detective and an Amazonian Warrior Princess.
When talking to Entertainment Weekly for this year's Comic-Con issue, Ezra Miller spoke about what it's like as the Flash when working with Batman (Ben Affleck) and Wonder Woman (Gal Gadot). “In Diana and Bruce, you have two very different veteran mentalities,” said Miller. “Wonder Woman has this powerful compassion. Bruce is more irritable, less tolerant. Barry’s in total awe of them. He knows this is the big leagues.”
It'll be interesting to see how Barry will look at Aquaman's (Jason Momoa) role when he finally decides to join the Justice League, or even Superman (Henry Cavill) for that matter.