Is it okay to mention Facebook jokingly in my college essay?

Specifically for UCs (Berkeley, LA, SD). I wanted to mention how I am the only person with my name on Facebook, jokingly, to show how unique I am. Would this be alright? I don't know how casual the readers generally are, so I am hesitant to adopt a less academic tone. Should I let my personality through in the essay-- i.e. joking tone and quippy jokes-- or should I stick to a well-written sob story?