The greatest discovery of my generation is that a human being can alter his life by altering his attitudes.

The quote comes from Harvard psychologist William James. The advice below is from a post by Brian Knight titled The Power of Attitude

“Your attitude is one of the few things in life over which you have total control.  Harvard psychologist Williams James: “The greatest discovery of my generation is that a human being can alter his life by altering his attitudes of mind.”   If you want to perform at your best, and if you want to maximize your happiness and fulfillment, then you must take control of the life-shaping power of your attitude.  Please understand: developing and sustaining a positive attitude is not merely a quick-fix motivational technique. It is a disciplined skill that must be practiced and learned.”

“Choose your battles wisely”

From an article at SixWise.com called How to Most Effectively Pick Your Battles …

We’re all given a finite amount of time in a day, and it’s up to each of us to determine how to spend it. In relationships (with kids, with a spouse, and so on), we’re faced with many conflicts everyday, and you may be tempted to fight through each of these conflicts, to ensure you get your way, to prove that you’re “right,” or maybe just because you feel challenged. But most experts agree: choosing your battles wisely is a much better way of life than battling out every disagreement.

Although they may seem important at the time, most battles are NOT worth fighting.

According to Dr. Richard Carlson, author of Don’t Sweat the Small Stuff … and It’s All Small Stuff, “Often we allow ourselves to get all worked up about things that, upon closer examination, aren’t really that big a deal. We focus on little problems and concerns and blow them way out of proportion.”

It’s up to us to choose to either make a big deal or simply let it go, and, according to Dr. Carlson, if you learn to choose your battles wisely, you’ll be far more effective in winning those battles that truly are important to you.