Just an update: I stepped on a large staple from a cardboard box on Saturday. It poked me right in the side of my ankle when I was cleaning. Walking is not too bad, but it sure hurt when it happened. But as my luck would have it, later on in the evening it still was bothering me. I thought I would check it out again, and noticed that I could feel something else still in there.
Sunday morning I went into the local medical clinic to have them have a look at it, and they noticed something too. The nurse there, managed to dig out another chunk of staple, about 6mm long, with some large tweezers. Now my ankle is in pain–but walking is still good.
This morning, the hole left from the staple is now swollen, so I changed the band aid, and cleaned it up.
It is amazing how it is the little cuts and pokes that hurt the most.
Lesson: do not leave flatten cardboard boxes laying around on the floor. They are deadly traps!