That moment when you realise that, if you're making corned beef pie for dinner, you need corned beef.
Now, maybe one of you wise people out there can tell me why they still put the tin openers on corned beef cans. They stopped doing it on sardines ages ago and, if it were such a good invention, why didn't they do it for anything else?
Not that I've ever had much success. The little key usually comes off in my hand leaving a dangerously-half-opened can and I have to resort to using a proper tin opener.