Most of these stories are a bit negative, here's a lighter one. My mum's a linguist and speaks about 15 languages fluently and as such, I picked up a couple along the way. Most of my childhood was spent in Germany so I have a firm grasp of the language...which doesn't really seem to match my appearance. I'm a 6'3, 220lbs, black man, who speaks German. Now this isn't too uncommon a sight in Germany, but in North America, I'm a f***ing unicorn. So I was standing at the bus stop one day in the heart of downtown Toronto and there were these two 60-something year old German ladies who were not having a good time. They were trying to find the Art Gallery and were fed up with the fact that they were having such a s**tty time navigating because their english-speaking children had left them alone for the day. I didn't have anything particularly important planned for that day, so I turned to them and said something to the effect of "You know, our city has a lot to offer if you know where to look. Would you two like me to show you where the Gallery is, and a couple places you can get lunch along the way" They nearly fainted. They were sooooo happy that they found someone who spoke German and couldn't stop taking pictures with me to show their family 'the guy that saved their day'. I walked them to the Gallery and gave them a bit of an impromptu walking/bus tour along the way. That was the day I gained two Omas.
I lived in South Korea for three years, but I never learned too much of the language. A friend of mine is 100% Korean but is very tall and was educated in America and New Zealand so she has an American accent. Her co-teachers at her school all assumed she couldn’t speak Korean so they would talk s**t about her constantly while she would listen on and feel terrible. She said nothing for a whole year until she had to speak at the end of year ceremony. The school offered her someone to translate but she refused and in front of 800 or so students and faculty members she delivered her address in perfect Korean. She subtly called out the coworkers that had spent an entire year calling her a foreign pig. Apparently one started crying from the shame of it. I wish I had got to see that.