Can't print only the selected image

It's always the simple concepts that escape me. All the LrC forum tips and help videos show the "simple" process of selecting an image in the develop module and entering the print module to print it. When I do that, the first image in the folder immediately displaces the selected image and Lightroom commences to print a copy of every image in the folder. My work around is to give the target image a unique color flag  then applying the appropriate filter to make it the only image on the filmstrip. What am I missing after my ten years of using Lightroom???