It's hard to have a good year if you feel like your brain is giving out on you, which is why this book on fighting cognitive decline as you age by CNN medical correspondent Sanjay Gupta makes Greater Good's list. "In his book, Gupta gives us five main take-home messages culled from neuroscience research: We need to move our bodies regularly (even mild exercise helps), get solid sleep, eat well, connect with others, and find meaning in life," reports the site. Check out the book for a lot more detail.