Perfect article for a time of year that can be stressful.
We often think it's our problems--our troublesome life circumstances--that make us unhappy, and that if our circumstances would just change to something more desirable, then happiness would be easy. It turns out, though, that it's not our circumstances that make us happy or unhappy.
A recent Harvard study reveals that stray thoughts and wandering minds are directly related to unhappiness.  The study discovered that those with constantly wandering minds were less likely to be happy than those able to focus on the tasks at hand.
This study seems to confirm what Buddhists, sages, and saints have long taught--that an unruly mind creates unhappiness and dysfunction, and that the keys to happiness lie in mastering the mind, and not in changing external factors in our lives.
This recent Harvard study only serves to confirm the results of research that has been conducted on meditation and mindfulness for over 40 years. Mihaly Csikszentmihalyi, one of the world's leading researchers in positive psychology, refers to this state of mind as "flow."
Csikszentmihalyi describes flow as being totally absorbed or immersed in the activity in which you're engaged. It doesn't matter what the particular task is--what matters is that you are fully present when you're doing it.
This hits the nail on the head on why I love climbing so much. When I'm climbing the entire world fades away and I'm only focused on one thing...in a state of flow.
Csikszentmihalyi, often called the grandfather of positive psychology, found that our happiest moments are when we are in the state of flow. In this state, we are highly alert. We are totally focused with one-pointed attention. This focus--this mindfulness of being in the moment--is when true happiness spontaneously arises. 
When you are mindful of your activity, you're not preoccupied with regrets or worries; you're not planning or wanting for anything. You're not lending power to thinking processes and so they do not dominate your awareness.
Flow allows you to truly and deeply live your life as it unfolds in the here and now. Perhaps this is why the latest research continues to confirm that mindfulness increases happiness--to be mindful is to truly experience life and make the most out of every moment.
Rememeber that this holiday season.