I can't believe it.
Three months ago I was invited to attend a private reception followed by a concert and supper at the Royal Festival Hall.
We were promised a "fabulous evening of Hollywood Soundscapes" and "entertainment inspired by the glamour of Hollywood".
Better still, "Our post-concert supper promises to entertain and enlighten with our guest speaker Joanna Lumley providing a fascinating insight into working in show business and alongside many Hollywood greats".
I was really looking forward to it.
But last night, as the London Philharmonic Orchestra played their Hollywood Soundscapes and Joanna Lumley stood up to entertain and enlighten, I wasn't there.
I got the date wrong. I thought the event was on Friday 21st October.
How could I have been so stupid? I really am a complete idiot.