I think we all experience a certain level of uncertainty at one point or another during the course of our professional careers and in our personal lives. Your post reminded me of Erik Erikson and his argument about the critical stage in the formation of one’s identity occurring during the same time you mention, college years, where most people are between late adolescence and early adulthood. Here is one of his quotes “The identity crisis… occurs in that period of the life cycle when each youth must forge for himself some central perspective and direction, some working unity, out of the effective remnants of his childhood and the hopes of his anticipated adulthood”. Glad you found your niche!