There was this girl in the school where I practiced the Flamenco. She was around 12, 13 and she had some cognition issue, which made her behave as if she was even younger. We all trated her as a baby.
It was the end of the year and we were rehearsing a lot for the annual presentation, there was a lot of tension in the air, but I was already used to it, so I could play this role as our teacher's assistant.
The day finally came. Everything was going well, so I could concentrate on my own choreography and feelings. I was waiting for my turn to go on stage when I realized that the girl had forgoten her sombrero - one of the accessories used in the Flamenco dance. I got very worried. I believed she would run away from the stage and spoil the presentation. I couldn't turn my eyes from her, so I saw all the process. When it was the choreographic moment of picking the hat, she realized it was lacking and started crying. Then she looked towards us with a scared look. But she kept dancing, miming the hat moves.
It was a great lesson of being on stage. It happened many years ago, but I've never forgotten it.