I'm going through ABGU again...well, I didn't actually make it all the way through it but I did a lot of it. Now I'm going back over a lot of stuff I didn't really master the 1st time through. That's one of the benefits of having lessons like this (instead of taking 'live' lessons). You can repeat the lessons as often as you want and take as much time between as you want. This time going through the course I have begun to develop a callus on the side of my right thumb from playing the thump bass. It started off as a blood blister. Not good. I'm taking it easy so as not to tear it open and it's beginning to form a callus. Also on the tip of my ring finger I've actually torn some skin off it. It's painful and it keeps me from playing some of the lessons until it heals. As soon as it does heal (hopefully in a couple days) I'll start using my fingers to pick the strings again (instead of using a pick). I'm looking forward to getting my fingers toughened up on my right hand so I can use my fingers to play some of this material the way it's presented. While my ring finger heals, there is still plenty of material to learn/practice using a pick.