What Does It Mean?

Today I went out and raked leaves in the playground area of our yard while the boys went bug hunting.  By the time I was finished there were six very full bags of leaves, twigs and trimmings from pruning the crepe myrtles.  It was satisfying work for the most part and a good work out to boot.  When I came back inside a few hours later I was in desperate need of a shower.  I went to my closet to take off my running shoes when I noticed I had double knotted my shoes! I've never done that before - at least not since I was a little kid. Am I the only one who's done that?