A couple of weeks ago, my daughter (approaching 6 years old) was making her lunch for school the next day. She wasn't making much progress on her peanut butter sandwich, and I noticed she was having trouble getting the lid off the jam jar (bad design, Smuckers: the big plastic jars from Costco, while cost-effective, are prone to sticky lids, and the jars aren't solid enough to really grab and twist effectively...but I digress).
Eventually she just looks at me and says, "Dad, you're a spork." I am? "Dad, you're a spork!" Apparently she means it, whatever it means. Why do you say that? "I'm trying to do something, and you're not being useful!" [beat...laughter all around the kitchen]
Some months earlier, probably while dining at some fine dining establishment that thinks it can save money by using sporks instead of spoons and forks, I had taught her the expression, "useless as a spork." It appears the lesson was learned and remembered.