Martin Seligman, Author of the book "Authentic Happiness" and pioneer of the positive psychology movement reports here on the extensive research indicating that the externals in life make almost no difference in how "happy" we are.
Of course that is, once a certain threshold of basic needs is met.
We all have a well established set point of happiness, which we default back to after life experiences both great and terrible. Lottery winners are happy for about 3 months, then return to their baseline. Paraplegics are miserable for about 6 months, then return to their baseline.
Seligman believes we can learn to live either at the bottom or the top of that set range.
He explains the there are three kinds of happiness that we pursue: The Good Life, The Pleasant Life and the Meaningful Life.
Take the test at his website to find out where your core happiness emanates from, how to identify your signature strengths and live in the upper part of your happiness range: