In an interview with Maye Musk, the mom of billionaire Elon Musk, the BBC reveals the horrifying abuse both Elon and his mom experienced at the hands of Elon’s father, Errol Musk.

In a clip, Musk was asked if he experienced a happy childhood. Musk responded, “No, it was terrible.” When the interviewer seemed to push for more information, Musk repeated, “no no no,” and appeared to be holding back emotions.

Maye explains that she returned from her honeymoon with Errol, “bruised and pregnant.”

Elon himself was abused by his father and bullied endlessly at school. At one point, Elon was pushed down a flight of stairs and beaten – leaving him hospitalized.

Knowing Musk’s history helps people understand why he’s such a fighter and why he tends to dig in his heels and push back when people push against his ideas.