I'm not as good as I was hoping to be but now have skills and knowledge of the guitar that I'll never lose. Speed is still a little slow (which is a bit frustrating), but I know some songs, have the major and minor diatonic and pentatonic scales down, and understand how a lot of the sounds I've listened to over the years are created. It is especially fun to learn a song, follow the instruction and recreate that sound I am so familiar with (albeit, not always as clean, LOL).
I've completed Rock I and II, and am about halfway through Blues II. Next will be Country, then back to Rock and Blues to catch what was missed the first time.
Also, enjoy all the links and ideas from the other folks on the forum.
Thanks to GT and everyone else who participates. You really can learn to play (even at 53) if you just follow the plan!