Starman Jones is one of my favorite Heinlein juveniles, and yet mostly seems ignored by SF fans. It is a hard book to find for instance, I only have an old, beat-up paperback of it.
But its a great story, and uses a couple of common Heinlein themes. Rebellion against some form of authority and the appearance of genius in an unlikely place.
Max Jones is the nephew of an astrogator but comes from the wrong side of the tracks so to speak. He inherits his uncle’s library of astrogation books and studies them determined to follow in his uncle’s footsteps.
But the guild is restricted and his library is confiscated when he applies. Determined to get into space and away from his hopeless life on Earth he runs away and gets onboard the Asgard.
The ship eventually gets lost in space and Max becomes the hero because of his illegally aquired astrogation knowledge.
He has the talent of perfect recall and unique mathematical ability. He saves the ship and crew.
Slipstick Libby is another character with similar abilities who appears in Methuselah’s Children by Heinlein.
A slipstick, by the way, is slang for a slide rule. That’s an ancient technology that most of you have never used.
Anyway, a great story of overcoming the odds against you and unlikely genius.