"Thank you."
/When I was in second grade, I wrote a ton of songs. There was one in particular that I was really proud of. I decided to share it with my music teacher after class one day. He listened as I sang, and then he said "thank you."
As a second grader, I wanted to be praised and told it was a great song, so his simple "thank you," which may have been sufficient in his mind, was the biggest rejection I had ever felt.
I kept writing songs well into my teens, but I never again shared them with anyone.