Later in my school career my potential lab partner who was black told me to never rush a black man. I got a new lab partner.
When I tried out for the bball team, one of the black kids told me they didn't allow whites on the team.
Have all of my experiences with blacks been negative? No.
But you begin to form opinions very early based on behaviors.
Every morning, when I was a Kindergartener walking to school, a group of black kids who were 8 or 9 would rob me of my milk money (5 cents). I was threatened not to tell. I resolved to walk to school the long way around the block. I had to leave 5 minutes earlier which my Mom thought was strange but I never told her.
That was my introduction to black people and I remember it. Have I known nice black people? Sure. Does my experience put an extra hurdle in the relationship? Sure.