I have always had a passion for the sky, be that skydiving, sailplanes or as I do now, paragliding, which turns out to be the cheaper and much more self sufficient of the three 🙂
I don't think you have to FLY as such, but I do believe the passion for all things sky like freeflight, GA, space, model aircraft and even mountain climbing above the clouds etc do go hand in hand. Many of the paraglider pilots I currently fly with have informed me lately of their interest and owned equipment in the astronomy area since I have posted some pictures on Faceache.
When you look at it, with an interest in space, the only way to get there currently is to fly, so maybe that is the common connection?