Follow your interests, being aware of your personal strengths and weaknesses. Software engineering is a good career choice for those of us who tend more to be generalists (we know very little about everything), because it allows us to move among many different subject areas. For those who chose to specialize (to know everything about very little), research in one of the sciences is a good choice. Engineering lies in between. Study math and understand it thoroughly, because it is essential for all of science and engineering.
Human settlements throughout the solar system, exploration of other star systems -- Star Trek.
I get to change jobs (task assignments) every 1-4 years without changing employers. Every task involves designing and learning about interesting technical systems; I get to design and code programs, and then to see them do interesting things, and my work contributes to a mission I believe in and to which I have devoted my career.
I wanted to go into space, any way I could. I haven't made it yet, but it is still my fondest dream.
I was 10 when Sputnik was launched, and that is my first memory of an awareness of space travel. I read Heinlein and other science fiction authors, built model rockets, and by high school was dreaming and planning to be part of the space program.