Today I learned (with the blank, trembling stare of a man sincerely trying not to pummel and subdue the truly lost) that there is now such a thing as 'Selfie Elbow' which - as you can probably guess - is like 'Tennis Elbow.' Or, if you've actually done real work in your life, this is when your elbow becomes stiff and painful as the tendons that join the forearm muscles to the elbow are over-used through repetitive movement.
There are people out there who have Selfie Elbow. An actual injury. From taking too many selfies. (I'm going to need some quiet time now.)