5th anniversary

Anybody care to guess what today is the 5th anniversary of?  Herewith hint.

To the tune of The Flintstones

Back pain!  You’ve got back pain!
Your nerves jumped you like a bunch of thugs!
Back pain!  You’ve got back pain!
And your only question’s, Where’s the Drugs?

Maybe… you have blown your L4 disc!
Maybe….yoga would have halved the risk!

Back pain! You’ve got back pain!
You’re in fashion now, you’re all the rage!
Back pain! You’ve got back pain!
Welcome to your middle age!