In a blog post titled "I love you, dad," Persson recalls the snowcapped moment he began to think of his father as a separate person, filled with "his own thoughts, his own wants and his own memories" Notch calls it one of his "fondest childhood memories."
Before he and his sister were born, Persson's father struggled with addiction, but "managed to get over it with the help of religion and will power." His father relapsed when Persson was a teen, and his parents' marriage unraveled as a result.
He and his father reconciled, and his father supported him even before Minecraft became a phenomenon. But his father continued to struggle with addiction, which lead to his untimely death one year ago.
You can read his remembrance in his own words — including a harrowing story of a dog, a dad and some thin ice — on The Word of Notch.