its funny you mentioned the policeman thing, i get that question occasionally.
if you are neighbours then after a while the novelty does wear off. my next door neighbours parents (who are elderly and dont speak english) will natter at me in cantonese quite easily, even so far as to recruit me on one occasion. a water pipe burst suddenly and my elderly neighbor bumped into me at the elevator, and wanted me to accompany her while we scolded the management office. the office staff was on the phone instantly trying to fix the pipe when he realized the old lady was going to sic the canto speaking gweilo on him! we shared a laugh after that.