No one likes to admit they have made mistakes, but being humble enough to admit to them is a strength. Frame your answer in a positive light by focusing on what you learned from the experience and how it has made you better at your job.

"During one of the openings we had last year, I was responsible for filling 25 openings at one time. I had back-to-back interviews scheduled for a week straight and it was difficult to keep the candidates straight. One of the positions I was filling was for an IT manager and I had several interviews lined up with candidates whose resumes all looked the same. One candidate had a really great personality and his values lined up with the company, making him the perfect choice for the role. Unfortunately, I didn't have time between his interview and the next to write down the notes I needed and at the end of the day, I was no longer sure which of the candidates he had been. It took me several days to reconnect with each candidate over the phone and by the time I had spoken with them all and knew which one I wanted to hire, he had accepted another job offer and was no longer available. We still ended up with a strong candidate, but not the best candidate. It was a painful way to learn an important lesson and I've made sure to always make my notes immediately following the conclusion of an interview, even if I have something pressing that is waiting for me. Too much is learned in an interview that can't be gleaned from a resume and it is absolutely crucial to capture that knowledge before it is lost."