Some students spend too much time using their cell phones to listen to music, watch movies or play online games and this will take much of their spare time.

Back then, no one was yet thinking of watching movies on their telephones, or playing games on them, or writing letters on them that would fly through space and end up on someone else's phone.

"Remember a time before cellphones, when you had to make a bazillion calls to try to organize getting a group of friends to meet for a movie?" he asks.