I wouldn’t say you’re sheltered, in fact I’d say it’s becoming less and less the norm. When I was growing up casual racism was rife, not necessarily even intended to offend, but the shop owned by Southern Asians would be known as something beginning with P and the Cantonese Takeaway would be referred to as a derogatory term for a Chinese person.
Now they’re much more politically correct terms and generally I think society has learnt to be more considerate and inclusive. We as a nation are far more well educated.
Regarding the wanker in your story, well that’s what he is. A f***ing wanker. I don’t condone violence but I probably wouldn’t have been upset had he ended up getting a slap.