It would have been around 1979 I think. I had been a steward at a Rock against Racism gig at the Rainbow Theatre, Finsbury Park. The stewards were given blue t-shirts with Rock against Racism and a picture of a rhino on the front. On the back was a large black 'PEOPLE UNITE'.
A week or so later I was walking along the River Lea from Clapton to see a friend in Stamford Hill wearing the t-shirt. I heard something behind me and looked back. About 30 yards behind me a young white guy, maybe 16-17 yo, was kneeling down encouraging his collie dog to run up the towpath in my direction. I immediately knew he was intending to do something to me.
The dog ran past me and he ran after it to appear to be chasing it. I knew he was going to barge into me and try to push me into the river, a yard or so to my right. As he got to just behind me I braced and when he collided with my shoulder he bounced off, stumbling and almost falling.
I had been doing self defence classes and took up a defensive/offensive stance. He picked himself up, mumbled something, and walked on after his dog.
If he had succeeded in pushing me into the river I would quite likely have drowned. It is fast and deep with high banks and I can't swim.
Perhaps I should have done him some damage when he stumbled, maybe tripping him and kicking him in the head or try to break an arm. But if I had it would have been me who got locked up.