At the end of the day, game development is all about people [besides making money]:
You spend most of your days working with a team, which becomes sort of a family. There are great times and times when you all struggle to work out the differences and ship the game.
You connect with other developers on social networks. Go to events and jams. Build a community. Market your game.
Your game talks to players and they talk back. It makes them happy, angry, sad. And players talk about your game to other people.

For their final [gamedev course] project, I ask my students to think about the following:

-What are my goals with the project?
-Which area do I want to pursue?
-What can I do?
-[Maybe more important,] what can't I do? (my constraints/must learn stuff)
-How many hours/week can I allocate to the project?
-How can I communicate with the team?
-How will I publish/make money with it?
-Did I check the project triangle? (fast, good or cheap, pick two)

I believe these questions help when starting a project.

Be humble. You don't know all the answers and you never will. But that is ok, as long as you are humble enough to hear other people's ideas and tips.