This plate belonged to my Grandparents, who would always say, "yes, when we get round to it". As a small child, it took me ages to get the 'joke', but then thought it was hilarious (as you do when you're 8!)
When we were clearing Gran's house, I requested the plate. It is truly hideous (he he!) but it makes me smile and think about them every time I use it (usually underneath a plant!)
So Beebarf, your round tuit is out there somewhere, you just have to hunt for it!!