3. Exercise

You don't have to run a marathon and you don't have to join a gym.

But good health requires exercise....getting your heart rate up, optimally, for a minimum of 30 minutes a day.  Don't look at me that way: no matter what your age or lifestyle or health condition, you can do something.

And yes, simply walking briskly counts.

Exercise will make you happier, make you smarter and give you more energy.

Exercise is good for younger folks but it's particularly important as we age.

Lastly...I understand that many of us think that we don't have 30 minutes a day to radically increase the quality of our lives.  So let's shoot for something more manageable, like 10.  Can you spend 10 minutes a day to feel better, get smarter, get more energy, be happier?  10 minutes?  Come on, sure you can.