I don't think it's a problem with mobiles phones, its today's culture, especially in the western world. "We don't care how you get the answer but we want the answer NOW and we wanted it YESTERDAY!" That's the reason why there is no effort or reason to retain information anymore. Everyone wants everything now, not tomorrow so a quick Google search and job done. When I was at school, we didn't have calculators for maths exams now they allow them. So you can get the right answer ASAP.