Park was born in the United States, the daughter of two immigrants: Kwansik Park, who was born in Korea and her mother who was born in the Philippines. Her parents came to the United States with virtually nothing, but managed to make enough money to send Park to university and medical school. She has at least one sibling, a brother. During high school, her intense study habits earned her the nickname "The Bookie Monster". It is not disclosed where she went to university, but what little we do know about her was eventful. Her roommate eventually went on to become the editor of Yale Law Journal. She lived next to a Jewish fraternity and, in her words, "tapped at least thirty guys" without forming any emotional bonds. However, she did have a steady boyfriend. While they were on "a break" to determine whether they really wanted a permanent relationship, he used the opportunity to sleep with three of her friends, then dumped her. As a result, she gained "82 pounds" and gained the nickname "Park-ing lot".
However, she continued to excel academically and finished in the top 2% of her class in medical school. She eventually wound up as a neurology resident at Princeton-Plainsboro Teaching Hospital, and since her parents also lived near Princeton, she started living with them again.