One of my favorite examples recently- after finishing a trip, i was walking through the terminal, wearing the blazer/hat combo uniform after commuting home, on the way to my truck, and as i walked by a mother who was with her child (about 4-5 year old boy i would guess), he shouted across the terminal hallway- " HI CAPTAIN!!!!!" .
Even though i'm an FO, i could see that it was clear i was the person he was talking too, so i said i quick "Hello!" back to him while walking by, and then he ran back to where his mother was sitting just smiling. And his mother i think was a little surprised/embarrassed, but hey, it was funny and nice.