Dropping the Ball

A few weeks back, a co-worker reported an intermittent email problem to me. . I was in the middle of something and asked him to send me a reminder. A couple of weeks, another co-worker reminded me about the guy's issue, but I was again neck deep in other work and asked for an email as a reminder. "Email is my short-term memory," I said, half-jokingly. A week later, I got a third request to fix the issue and realized that I had totally dropped the ball.

Today, my manager asked me what happened and I freely admitted that I failed to handle things properly. The manager asked me what I could do to prevent it from happening again. I offered to take a pen and paper around with me. Here's the thing... I failed to follow up. I'm the one who forgot. But does this totally abdicate the people who told me about a problem in passing? I asked them for some sort of reminder. Seems like a reasonable request to me. They didn't send the reminder, and then got bent out of shape and emailed my boss when I failed to respond. I'm not trying to skirt around or minimize the fact that I didn't follow up, but Jeebus, where's their portion of responsibility?

/Rant
I guess it's time to adjust my expectations. The person who complained to my manager is one of those people who just can't be trusted. I see how she works now.