It's the state of Android updates. Google makes a new version of Android. New version of Android goes to the phone manufacturers (HTC, Sony, Samsung, LG, etc). They put their "skin" on it and test to make sure everything works. Then that version gets sent to the various carriers who want to install their own apps and then it has to get tested on their own networks AGAIN to make sure nothing's broken. Once all is OK, THEN it finally starts getting pushed out to consumers - in a staged roll-out, meaning your buddy may get Lollipop on his Rogers Note 4 but you might have to wait a week or more before you see the update on your device. It's a unique system - but it's the price you pay for a more "open" and customizable OS then with something that's locked down like iOS.