One of my favorite travel memories:
Frankfurt Airport is like a game of chutes and ladders, escalators going every which way. I was heading to my flight and noted an elderly Eastern European woman in typical frumpy garb standing at the top of a down-going escalator, puzzled and concerned. She'd obviously never seen such a contraption before and was terrified she'd fall. I walked around and ahead of her, turned around, smiled, offered my hands, and (walking backwards) encouraged her to step onto it. She hesitated for a long moment, then took my hands, and bravely stepped on.
Then her face brightened, and she giggled like a schoolgirl all the way down.
Neither of us spoke the other's language, neither of us knew where the other had come from or where we were heading, and we'd never meet again... but we intersected for perhaps a minute in the middle of one of the most bustling transport hubs on Earth.
I won't soon forget her laugh.