Last week, I was in a meeting in which one of the participants was particularly terse toward me.

After the meeting, I learned from another participant that it was probably because I hadn’t responded to an email he had written earlier that week that ended with a plea to “respond today so I can sleep tonight.”

The problem was that I had never seen the email. It turns out, it was written as a response to a meeting invite. My settings for meeting invites is that I get an email notification each time someone accepts or declines the meeting. Because he had responded to my meeting invite, it came through with the same subject line, and I deleted it without looking at it, thinking it was just a meeting acceptance.

When I explained this to him, he said, “that sounds like an excuse.” But I thought of it simply as a reason why. Which got me to thinking: What’s the difference between an excuse and a reason why?

Is it the intent of the accused? When someone asks or expects something of you, and you give them a made up reason why you failed to mask the fact that you either forgot or just didn’t want to do it, that would see more like an excuse. Conversely, if a real obstacle got in the way, that would be more a reason why.

Of course, real reasons are easily established with a bit of expectation management. As soon as you ran into the real obstacle, a simple note to the person expecting something of you would give them time to plan or react and establish you ran into a real issue.

Then again, perhaps the distinction between an excuse and a reason why lies with the person affected. If someone is expecting something from you, and you only give them a reason why it’s not finished, perhaps it’s up to them to determine whether or not what you tell them is an excuse or a reason why. It would depend on whether or not they believe you, think it’s legitimate, or consider you lame.

It’s a fine line between excuse and reason why, and it seems very arbitrary, based on the trust between the person who made the promise and the person who suffered the broken promise.