Slightly off topic, but my three most alarming experiences of "personal space invasion" occurred in Morocco. DF and I were there in March '10 and in the span of 15 minutes someone came up to me and put snakes around my neck without asking and said "you pay. You pay." Then, some woman came up to me, grabbed my hand in a death grip and proceeded to tattoo my hand (not permanent) and then some random dude came up behind me and smelt my hair. This was on my first trip to visit DF. So, it was only my second time out of the US (I went to Ireland in '05). I thought it was going to be 10 days in London, but he surprised me with short break in Marrakech. So, I was very unprepared for it. I'll have to think of this next time I get aggravated in the grocery store. 
Suddenly, the Blackburn Morrisons seems a lot easier to get through than it did before. Now, I will think 'well, it could be... (insert one of the above examples)'.
I've only had a snake dropped around my neck once. I was 10, and it was at a petting zoo type exhibit. Without thinking, I hysterically said 'Get that f****** thing off me!' I can only think I had learned the word from my teenage uncles and their friends. Mom never said a word about me saying it because she doesn't like snakes either, and because I'd never used the word before and have rarely used it since, because I don't like the word.
Another thing I have mastered is dodging people while walking down the sidewalk (yep, I still call 'em that). In the States I drove, and although I had a lot of sidewalk experience, I never lived in a city where I had to walk a lot. I've learned there is no rhyme, reason or logic to how people get from point A to point B by foot, but I have learned how to keep moving instead of stopping to let people through all the time.