You want to try and bring a character to life in an honest a way as you possibly can. It doesn't matter whether he's a doctor an actor a car salesman or a captain of a starship. If you can bring truth and honesty to that character then your audience will believe you.
I got to spend all of my time every day at work reading and editing papers about cutting-edge technical research and getting paid for it. Then I'd go home at night and turn what I learned into science fiction stories.
