Sarah Phillips was raised on a luddite colony in the backwoods of the Alpha quadrant. Her grandparents, after seeing the horrors of the Federation-Klingon War, gathered together with like minded individuals to form a colony on a remote planet where they would eschew modern technology and outsiders as a way to protect themselves. Throughout Sarah's life she overheard (often drunk) elders let slip about an incredible galactic federation of planets, and miraculous technology like replicators and transporters, but when she confronts her parents and various authority figures on the matter she was rebuked and hushed.
One day a stranger comes to the colony after their shuttlecraft breaks down and strands them there. Mistaking the human commune for a provincial Federation colony, due to their speaking Federation standard and modern, if dated, clothing, the stranger asks for Sarah’s help with repairing their craft, exposes her to modern tech and proves to her that her dreams of life among the stars were not lies. The stranger realized their mistake, but the seed was planted. Sarah knew her place was among the stars, and begged the stranger for passage to the Federation.
Sarah left her home, and everything she knew, at the young age of 15, and became the first human in her colony to see the world from above in almost 100 years. Making up for lost time, she spends the next several years in the Federation (remedial) education system, and eventually joins and graduates Starfleet Academy at 30 as a science specialist, with her degree in exobotany (with focuses in gene editing, surveying, and whole-planet restoration) a homage to the agrarian background of her colony.
She's always been embarrassed by her stunted knowledge of things, and does her best to hide her dated upbringing. This makes her come off as shy and a little standoffish, but in reality she's eagerly drinking in every fact that this brave new world has to offer.
