A different kind of training

I was having a deeply philosophical run yesterday through the forest. I went there to clear my head and ended up thinking about the comparisons between training and life philosophies.  
In training for any sport we purposely but ourselves through stresses and seek out new challenges. We do this in view of bettering ourselves, unlocking new abilities. We constantly seek ways of pushing limits. Why then does it feel like we often try and find comfort zones in our mental and emotional states? We try and avoid stress. Perhaps we challenge ourselves in some way but it is highly unlike the grueling and relentless way we strive to improve our bodies or physical abilities. Our approach to it is different.
How often have we found that by pushing ourselves further out of our comfort zone, that our initial hurdles become obsolete? That what used to be our workout now becomes our warmup? What makes us thirst for new physical challenges but makes us recoil from any emotional ones?

By illonapelser