I was a big NBA (Lakerss, then Nuggets, then Raptors) fan from the early 1970s to early 2000s and probably attended games well before most posters were born.
My dream job when I was teenager was to become a baseball statician. I did not become one but I was involved in a few arbitration cases in the late 80s and early 90s. Sadly, it was not nearly as much fun as I expected. In fact, it was really boring. But I can't complain as it did put me in a chance contact with the woman I married.
As for being a casual fan, I am perfectly fine with the description. I rarely watch games if they don't involve the Raptors or (sometimes) the Timbervolves, but I do like building data model.