I enjoyed chess in my youth with only a playful interest much like any hobby.  Years and years later after finding many more learned opponents, I picked up a book on  Chess Strategy by Jeremy Silman around 2005 just to see if I could improve.  I discovered a new and exciting adventure.  

I still have my book with a heavily taped binder, loose pages, tons of notes  and well worn.  And still, I have just gleaned the surface.