You could put someone's eye out with that

I put my slippers on and went downstairs. Then I discovered there was something in my right slipper as well as my sock and my foot. A penny, I thought. So, I went back upstairs, took off the slipper and took out the penny. I put the slipper back on. I opened my jar of small change and tossed the penny. It struck the side of the jar, rebounded and went back into my slipper. So I left it there. Sometimes you have to know when to give up.