at 7 weeks is when i really started to feel better. im just about his age also, 23. and at 8 weeks i couldn't believe how much farther along i was. i have also been doing cardio rehab since prob 2 1/2 weeks. i credit much of my improvment to that. and its not so much of the speciality of rehab but the fact that it MAKES you do the workout and be active, that i think helps the most! at my rehab we have very basic equipment and just moving and getting your muscles all working is prob the most important! everyone does prob vary a little bit on their recovery but i would think that he would be more active. i was excited about showing off my new battle wound and talk about my surgery since this is all new to me. so it could be part of his social anxiety. i wish you the best of luck and i hope that he gets out more and more as time allows.