Stumbling on Happiness

I started to read a book call "Stumbling on Happiness" by Daniel Gilbert. Only a couple chapter, but yet the meaning of "Money can't buy happiness" I totally get it. I have a couple questions about happiness and hopefully the book can reveals on how our mind works? and What make me happy?
Friends always told me I am too demanding, yet I am a perfectionist. Satisfactory come from achieving goals, and I always have a plan for me to follow it. Which makes me unhappy, why? Because things might not always goes by what you planned for. To understand and solve this problem I need to know how my mind works? And what is my purpose of life? If I have kids no doubt that they are the purpose, but what is my purpose now?
Here are some of my goals in the next 18 months:
One of my new goal is I am going to do 70,000 push up in a year!
Bike to the top of Mt. Diablo.
Travel alone (never tried before, so it would be a new experience)
Double the size of the company and department.