Wait until you get to the two finger major A form barr. You have to push your ring finger's last joint until it is hyperextended flat on the fretboard. Once you get that you have to start working the position, until it can hold down the D, G, and B strings with your ring finger. All without touching the high E, the A, and the low E strings, which are held by your pointer playing the Barr position . It has been a while but I still remember thinking I would never get that chord. It is a contortionist crundrum for sure. There are bazar Jazz Chords that are also difficult, some streaches seem like they might pop a ligiment... but that hyperextention in the A barr, took me a long time to get comfortable with.