Well, genetics is one factor, i would think. But personally I place the biggest factor on what one does with what one has.
Its easy to say "oh, i'm sick because it runs in my family .... and I am sure that is the big cop out for the majority of heart patients, diabetes sufferers, fat people , arthritic, and on and on.
Anyway.... very glad you are doing well. We will have to have an arm wrestling match when we meet up . 555 just kidding, I am a wee bit older than you . The famous orthepedist in CM , after he checked me, put his thumb up . "you are much better than most people i see " .