This happens around once a year. I turn up to a meeting to discover that it was actually in the preceding hour and I have missed it. Hey ho. I don't think they really missed me. At least it wasn't a meeting I was chairing. So I've spent the last hour in the meeting room waiting for the next meeting, which also takes place in the same room, which I am chairing. And at least it supplied my blip.
The only thing I am really grumpy about is that my bike chain managed to fall off and consequently I now have the blackest hands in the universe from grappling with it.