Enrolled in ground school twice. First just before Desert Storm, second just before 9/11. Bad timing, both got derailed. Aero clubs permanently removed from air bases after 9/11. From time to time I think about pursuing again, mostly after a few beers . Now retired. I actually just ordered (today) Pilots Handbook of Aeronautical Knowledge / Airplane Flying Handbook Combo. At this point cost vs actual use is the biggest deterrent. I figured in my spare I can do some reading. Who knows, books are just a few bucks. If I do decide to go for it I'll enroll in an actual ground/flight school. There's one at a local airport 15 minutes away.
I think it was 4 lifetimes ago....when I had a little money in my pocket I spent some time in a Cessna 150 --- 60 hours and did all the paper work and tests, just never did the flight test. Life got in the way.