In Class: College Life

I've been realizing recently that it is almost impossible to graduate from a four year college if you do not go in knowing your major within the set four years. I've been frustrated because I came into TCU knowing that I wanted to go through medical school and be an opthomologist (an eye doctor). I wanted to do surgeries for the rest of my life and then I realized that although I loved the medical field very much that I did not want to be in school for the rest of my twenties. I changed to nursing and because I changed late they are now saying I will graduate in a frightful six years rather than four or even five years because I decided my major late. I now have to transfer home to the University of Colorado Nursing School in order to have even the slightest glimmer of hope in graduating within my four year time period. My question is, why do they call them four year universities or four year colleges when if you have no idea what you want to do for the rest of your life there is no possible shot for graduating in the said "four years." I think the universities and colleges nation wide have formed an alliance against people wanting to graduate in four years and I am convinced that some of the schools may even may for advisor's to say, "change your major as many times as you want" without telling the students that there will be many more years of payments, papers, exams, etc.