The mind is a powerful tool that can be used to harm or help our soul. Just as positivity is contagious so is negativity, as you are saying. Simply recognizing this negative energy we feel is not enough... we must get up and train ourselves to keep moving forward! Someone can understand how and where the negative energy is coming from but not do anything about it, which will only eat away at you for as long as you let it. I think a lot of the training you speak of has to deal with getting ourselves out of our 'comfort zones' and embracing all the world has to offer. Good post, love the motivation :)