From Don't Let Others Rent Space In Your Head by Gary Coxe:
One of the most annoying solutions suggested by friends and experts alike was to simply think positive. I strive to look for tools that people can use to accomplish things once they feel motivated.
One of the real keys to happiness is to understand the entire process of personal achievement and all of the success components as well. Depending on your situation, positive thinking and affirmation can only make you feel even worse.
Motivation alone may feel good for a little while, but rarely produces the results people rightfully demand in the long run. Accomplishment requires work.
