Balder  is the only child of Theresa and Frederik Mercury, a secretary and math  professor. They chose to wait to get a child until later in life so  Frederik could move up in his career. For this reason Balder grew up  with parents who were a decade to two older than his peers. 

This  together with his cautious personality made him more attentve to any  signs of discomfort so he'd be able to help when old age caught up to  his parents. In some ways Balder recognise that he was more of a  caretaker than a son. He wouldn't describe his childhood as abusive, yet  at the same time he seldom got time to think about himself because of  his caretaking tendencies.

Young  Balder had a great relationship with his grandmother. Looking back he  describes his time with her as those few times he could feel like a  child with no reprecussion. At Balder's baptism she gave him a bead with  an orange sun on it, and he is still wearing it in his hair today. In  fact he has made it a tradition that every year on his birthday he'll  add one more bead to his hair in honor of his grandmother - most of  these beads are turqoise yet at this sixteenth birthday Anastasia, his  half demon friend, gave him a white bead with a moon.  

One  of Balder's most cherished memories outside his time with his  grandmother was when his mother taught him the story of his namesake.  When she was younger she had wanted to be a professor as well one  specialist in mythologies, and so she'd always been endeared by the myth  of the Norse god of light, the kindest and most gorgeous of the gods.  This story kindled Balder's own interest in mythology so he'd spend many  a night digging through Theresa's mythology books learning all about different gods of old.