Want to forget a wifi network?  You can!  If you accidentally connected to a wifi network once, your device remembers it for life—right?  Wrong!  There’s a way to prevent that annoying wifi pop-up.  Go to Settings > Wi-Fi.  Find the network under the ‘Choose a Network’ heading. Select the blue arrow next to the network you’d like to remove and tap the button on the top that says ‘Forget this Network’.  And it’s gone!