I would be remiss if I didn't point out that my time has been filled with more than just buying books. There are always plenty of things to do - including "normal" life. When you work full-time, at a not-particularly-high wage (though still plenty for the frugal), you start to find limitations. Martial arts, fitness training... even music lessons - music keeps the brain fresh, and music is one of the things that makes humans what they are. Plus, it's one of the few things you could trade that you wouldn't lose or use up. Alright, except for strings, maintenance...
But there have been plenty of other things - putting fences up, getting ready for the arrival of spring, and all the work that will be needed in the garden. I've been putting off moving a grape vine that's not doing particularly well where it currently is... There are several that need to be planted this season, plenty of old (and less useful) trees to be removed - albeit slowly, as newer trees are planted and grow.
I've also been playing around with solar panels (although I have certain reservations about them), making solar thermal water heaters, solar dryers... I've also found where the nearest recycling depot is - so my coming annual holidays will see a trip or two, and hopefully finding some usable things like washing machine motors (very good for wind generators), water heaters usable as alcohol or water stills... Which reminds me - I have those solar still plans that I should try...