Juan grew up in Taichung, Taiwan. He comes from a military family: his father is a soldier, his mother is a military nurse, and his younger brother is an airforce pilot. As a competitive swimmer in his early years, Juan's numerous achievements and awards (including first place at the Taichung City Duathlon) gained him admission into the highly prestigious National Teaching First Senior High School. However, owing to his rebellious streak as a teenager, he eventually dropped out; only graduating after numerous transfers in five different high schools. Thereafter, he held several part-time jobs.