Murphy's law or just bad luck?

The other day I wanted to buy a roll of hockey tape to tape the blade of my hockey stick. I went to 4 or 5 different stores but I couldn't get the tape. I could have bought just about anything from boxing gloves to table-football, or even the complete golf-gear if I had wanted to. Except that tape! Have you ever noticed how sometimes you can get everything except the thing you're looking for? I sure have! I wonder, is that another one of the famous Murphy's laws or is it just plain old bad luck?