Write about something that you heard that you wish you could unhear.

 I once heard a rumor that a classmate lied about others, which made me distrustful. Later, I found out it was false, and I wished I could unhear it. The rumor changed my perception of that classmate, and learning the truth was a relief but left me with regret. This experience taught me to avoid believing gossip and to focus on getting to know people for who they really are.