is it possible to be better than when your graduated high school

I'm trying to reach my goal of being an astronaut. I'm an average student only recently (last year or two) got the drive to be an astronat and try in school. I'm doing great, I'm on an ROTC scholarship going to an aeronautical university to get my bachelors degree. However, I saw a principle scholar who is better at science and math then me and goig to University of Florida to study my major too. Im worried about my work ethic and academic inferiority. Is it possible I can reach my goals even though in the past I haven't been consistent?