I was late, stressed and having a panic attack and generally making a complete tit of myself when I couldn't pay for parking, when a nice lady came and payed it for me.
We were on a really long car journey and my DS (aged 2 at the time) was throwing a right wobbly because we hadn't brought him ice-cream. He kicked the table and split all the coffee, everyone around was tutting, but the staff were lovely and made no fuss at all and came over with a replacement coffee for free.
The first time I was away for work, I was flying to San Jose, but got transferred to San Francisco instead at 3am, some people on the flight helped me out and let me ride in their taxi, I was extremely grateful!
When I was a student catching the train back to uni (6hr + train trip), I sat down on one of the last available seats, just to realise I had sat down next to a very drunk, very chatty Glaswegian. 10 minutes into the journey i realised that i was going to be stuck, listening to stories about how he rescued a baby, how pretty i was, did i have a boyfriend, (imaginary boyfriend quickly invented). I was rescued by a lovely old lady in the seat in front who insisted that i needed to sit with her as we were both getting off at the same station, she was lovely and chatty to the man and I was very grateful to come and sit with her.
i was very down and crying walking around my local park, a lady spotted i looked sad and chatted to me and let me pat her dogs, it was a small thing but made the world of difference