I'm a 32 years old teacher in mathematics and physics in a high school, and I obtained a first class BSc (Hon) in physics a couple of years ago, which was emphazided on theoretical physics in terms of option courses. However, I have always wanted to gain an MSc and, if possible, a Phd in theoretical physics, and for this purpose I plan to apply for an entry in 2010 at Imperial College London (MSc in quantum fields and fundamental forces). I have already taken a look on the programme on the net, but the question I would like to know is the following: how much is this Imperial MSc demanding, especially for mature students, if there is? are the courses so hard as paople say, especially string theory course, or do you have to be a genius to understand that? And also, is there any chance for a so aged as me to pursue in a Phd in theoretical physics, or is it hopeless?