I'm fortunate, though: it was never because of my skin colour, so I don't know what that feels like.
My Upper School was quite segregated, with social groups formed largely around skin colour. I remember the 6th Form Common Room had an archway in the middle, splitting it in two. One side, quite organically, became the 'white' side, and the other was the 'black' or 'Asian' side. Looking back, it was a pretty horrible thing to happen.
As I progressed at that school, my friendship group changed. I became friends with the so-called 'Asians'. (The fact that most of them were probably born in England was lost on us back then.) I think fondly of the times spent with them over the years that followed: five-a-side football and table tennis in the sports centre; doing crossword puzzles or playing chess in the library; drinking coffee in the canteen while discussing video games. Normal things, really.
This group of friends was nicer to me than any group had been previously. I didn't share their skin colour/faith/cultural-heritage, but it didn't matter.
I remember clearly a conversation I had with one of my former white-'friends' (who had also been one of those who picked on me often). He approached me one break-time as I went to the vending machine.
'Why are you hanging out with the Asians?' he said.
I looked at him, slightly puzzled. It seemed obvious to me.
'Because they're my friends!' I said. (I'm proud of my younger-self for that response!)
It saddens me that we live in a world where racist ideas and thoughts are still so pervasive. Almost an entire year group of white people seemed to be growing up with the opinion that race made a difference to someone's value as a person. I don't know where most of them are now, or what their thoughts are. I can only hope they have matured into kinder people, but it's not hard for me to believe that any 'white' population might, largely, have racist beliefs underneath.
Racism is everywhere. It's constant in the unconscious (or not-so-unconscious in many cases) bias that all of us (including me) carry as a result of our culture and upbringing. There's no point denying it: it's there. But, if we recognise it in ourselves, we can challenge it, choose to act or think a different way, and change those biases for good.
We don't live in anything like a fair world: I can walk around with my white wife, without even having to think about what people might think of two people of our 'race' being together. A black or 'Asian' man with a white partner probably wouldn't have that privilege. And that's just one example straight off the top of my head.
The other day, I described the police as people who are supposed to be our 'protectors'. I'm not sure that would be the first word that came to mind for many black people, even before George Floyd's murder.
Yet, it's not just the American Police that needs to change. We all do. Let's start now.