I was travelling home on the train after a school visit. That morning, I'd had to get up at the crack of dawn and leave the house at 6.30am (groan) so it had been a long day and I was still travelling back 12 hours later. Drawing to keep awake, I was trying to be surreptitious, sketching with my book under the table between us, but I was spotted! Luckily he was really nice and liked my sketch:
I got into one of those lovely conversations that sketching sets up, connecting with random strangers. He and his girlfriend looked right through my sketchbook. They were staying on the train all the way to Edinburgh and had hours to go, so I was very happy to get off at Sheffield and stagger into a taxi home.