Tell me about a time you made mistake?

One time, I made a mistake at work by sending an email to the wrong client with confidential information. I immediately realized my error and sent a follow-up email apologizing for the mistake and asking the client to disregard the previous email. I also informed my supervisor about the mistake and took steps to ensure it would not happen again in the future, such as double-checking email recipients before sending important messages. It was a valuable learning experience for me in terms of being more careful and attentive in my work.