If you ever wanted to know what secret information your Olympus camera is recording about itself, including things like number of shutter activations, flash activations, failure codes and many other things, the procedures outlined here will tell you:
http://www.biofos.com/cornucop/hidden.html
Section 1 is mostly about the legacy cameras and Section 2 is mostly about the current cameras such as the OM-D series. If you choose to explore this information, be sure you have a fully charged battery in the camera and read the instructions carefully before you push any buttons.