It's terrible. It happened this weekend and I feel so angst-ridden about it. Incredibly guilty. I wish I could block this out of my mind, but I know I can't. I'll start twitching before long.
The reason was, you see, I was so sure I had no more obligations. I was so sure I was completely free, that I forgot that I still had to prepare to spend time with friends. I've let them down, and basically been a terrible friend in that regard.
There's really nothing I can do to make it up to them. So I suppose I'll have to wait until my guilt naturally dissipates.