I remember in the early days of our being in Afghanistan, there were a few media pieces reporting that they remembered the last time the British were there, 100 or 150 years ago. The tone was very much that it was somehow surprising the Afghans brought this up again.
Yet Britain and the US are built on national history, myths and memories. The US has a huge national story around independence and the push west into the frontier. The UK has our tales and myths of 1940 and 1066. Scots still remember "the 45" (that's 1745). Why wouldn't Afghanistan or Iraq?
Personally, my eyes were opened quite a while ago when the US dropped one of the largest conventional bombs on some mountain region in Afghanistan where they suspected Taliban leaders to hide out. The next day some guy on Reddit wrote (loosely paraphrased) "Hey, that's were I always travel with my motorbike! Glad I wasn't there when that bomb went down..." and posted a picture of where the bomb hit, with his motorbike in the foreground.