I'm a designer but I'm not a video game designer. I went to an art school and had the pleasure of taking some of the game design classes. Also got to learn from some of my classmates and why they chose a career in game design. Most of my classmates had a passion for complex problems and telling stories. They could be playing video games all day. Also, another trait was deconstructing the games they were playing and reading all about it online. They also loved sketching characters and coming up with game board games.
That was my observation, hope that helps!