After working 3 years in my current job and my boss hating anything to do with unit testing etc, I used my spare time to refactor our Makefiles to allow for the creation of unit and integration tests. I technically didn't tell my boss about it, so my heart was in my throat when he Skyped me with 'what did you change in ...'?

After having bashed any workflow with testing in it, I showed him the new workflow and automatic testing in Jenkins and he was actually enthousiastic, just like all other employees! I was hailed a hero in the R&D department, after all this time we can finally write universal tests. :D

Successfully juggling razor blades.