I've been to a few morning after wedding brunches and I've never gotten an invitation for one, so I kind of assumed we didn't need to send them. Then I got a wake up call, when we found out we need to give a head count for the brunch. I wish I had thought of this and included it on our response cards, it would have made life easier. Now we have more responses to track down. And our guests are probably thinking they just rsvp'ed. I had to whip up some invitations because we didn't realize this until about 2 weeks before responses are due.
Did you overlook something that created unexpected extra work?