proton size?

I woke up this morning feeling maybe smaller, maybe less energized. In fact, a new study in Nature calculates that the proton is 4% smaller than previously thought or as this Scientific American headline reads "proton shrinks in size" http://www.scientificamerican.com/article.cfm?id=proton-shrinks-in-size. So perhaps my jeans really do fit better today because my protons are smaller than they were last week.

What do these studies imply? Does this mean that we don't understand the basic structure of the atom as well as we thought? Does a 4% difference matter? Perhaps there was a calculation error and this newest technology that was used in this experiment is just off somewhat. Since now the Rydberg constant would now be different, does this through a glitch into the whole concept of quantum theory? Should we care? While protons are measured in femtometers are a lot smaller than nanometers (1,000,000times), all matter is composed of protons, electrons and neutrons. So when someone says your protons are smaller than they thought, you should take note.