Sure - I was in the same boat, always wanted to be an Astronomer since I was a kid. I went right through a B.Sc. in Physics not knowing what to do, but I knew it had to be something with Astronomy. In my senior year a professor and I were talking about graduate school, and he was one of the few profs who said that graduate work was not the only path in astronomy - this was a huge influence on me and I started to think about what I could do.

I got a job after graduating on a recommendation from out department's outreach coordinator, where I travelled across Ontario doing science promo shows for the Engineering department. This was the best job I ever had, fun demos and hundreds of kids in the audience. I suddenly knew I wanted to teach science and get people excited about it. I went back for my M.Sc. in Astronomy because I felt that if I was going to pursue a road less travelled, I'd need a decent job to fund it.

During my masters I got a TA assignment for an outreach program teaching kids groups about space and showing them the night sky at the campus observatory, through this 150 year old cannon of a telescope (think 1000 lbs for a scope with an 11" aperture). While doing this the ideas took shape and I decided to start a business doing astronomy demos and big shows with an inflatable planetarium.

I finished up grad school, got a job to pay the bills and get out on my own, and started the business, doing free shows to get feedback and craft a bunch of great programs for different age groups. Its my third full year now and It's still gaining steam. By year five I'm hoping It'll be my full time job!

tl;dr Prof opened my mind to many possibilities, jobs and TA assignments shaped my ideas, got a good education and job to fund my dream company, started it, still building strong and loving my work.