The Stupid Back Button on Android

Does anybody else find the back button on Android a bit retardted sometimes? I've never really had a problem with it but it is true you never know what its going to do.

For example: I was using the Verge app in Android Army and also going back and forth between messaging (GS3 Stock ICS Messaging App) and for the life of me could not figure out why it landed me back on the launcher home screen everytime i pressed back. Clearly Im trying to go BACK to the previous screen.

Wtf...