This is not a sensible argh, but still...
Last night I realised the date and realised that a relative-by-marriage has a birthday over the weekend. Quick, find a card. This morning I got the card book out, and didn't have much of a choice.
I did have one really good card...but I also know that this relative-by-marriage is pretty soon no longer to be a relative (due to the impending lack-of-marriage) and birthday cards won't be sent. So I'm thinking do I really want to use up a good card on this person - but still I must send one at the moment for the looks of things (i.e. so it appears I'm not aware of upcoming separation...)
Anyway, I cave and decide that despite this being a really fab card that I'd wanted to send to someone else, it was the only card available so I'd send it.
And I start writing it, "Dear XXXXXX" and then I go 'hang on, isn't this birthday in MARCH, not MAY?'
And I don't have it written down, so I get hold of my brother to check, and he confirms it was indeed in March. But I only realised this
once I'd written the name in.
So now I just have to bin it. It's silly to be annoyed by this, but it was a good card and now I can't send it to anyone as I don't know anyone with the same name

And usually I'd hold on to it for 10 months but I don't think we will be talking to this person by then, probably not on birthday card terms anyway!