At least he told me so one day.
When he was five and I was eight, he said that from now on he didn't want me to call him "my little brother" anymore -- but "my little witch."
He also started dressing in black. His favorite piece of clothing became a black pointed hat.
It was a fascinating transformation to see a five-year old telling people about their future. And some grown-ups thought it was strange when he walked up to other children in kindergarten and said to them: "you are going to be successful" or "you are not going to be successful."
I don't know if I ever truly believed any of this, and as we grew older, one would think this witch-business would stop -– but instead it intensified. I remember when I came to visit him in his first office at his first company. We walked around, and then he said that the witch inside him had told him that I should invest in the company.
In the end, he moved to New York.