...consider it to be just another one of life's little challenges.

It really is OK to feel irritated by something like that, but try to keep your powder dry. Tell them that it's on you this time, but you won't believe them anymore if they make another commitment they don't follow through on.

If it happens again, it's your turn to follow up with your commitment to not believe them anymore and then go about your own business.

Trust is a funny thing. Once it's broken, it takes a lot to get it back.

And that's all I have to say about THAT!