“To be tested is good. The challenged life may be the best therapist.” — Gail Sheehy

Three stories merge into a single theme today.

The first involves Angel Cabrera’s grueling victory in the Masters yesterday. Next comes the birthday of chess champion Gary Kasparov. Finally there is a play in last night’s Chicago-Milwaukee game in which the Brewers’ Prince Fielder tipped his cap to an opponent who had just robbed him of a home run.

What do they have in common? All three cases underline the extreme difficulty of achieving anything worthwhile. All involve competition at the highest levels.

One of my favorite quotes is: “When you’re wrestling a bear, you don’t quit when you get tired. You quit when the bear gets tired.”

The higher you go on the competitive ladder, the longer it takes for the bear to get tired.

You can view great opponents in one of two ways. You can either see them as obstacles to victory, or as vehicles to victory. Great opponents can bring out the best in you, and thus deserve appreciation as well as respect.

Fielder showed this respect last night. He hit the ball out of the park, but Reed Johnson of the Cubs jumped high and caught the ball well over the wall. Instead of hanging his head or showing his temper, Fielder tipped his batting helmet in Johnson’s direction.

Cabrera survived a great field, and then a three-man playoff, to win the Masters and the green jacket that goes with it.

“Something was running through my body,” Cabrera said when asked what it felt like to put on the jacket. Golfers appreciate the jacket precisely because it is so difficult to win.

Kasparov, who turns 46 years old today, was a longtime world champion. In his book, “How Life Imitates Chess: Making the Right Moves, from the Board to the Boardroom,” Kasparov recounts the physical, mental and emotional effort needed in his victory over Anatoly Karpov to retain his title. You can read excerpts here. The move-by-move summary is here.

To summarize: The greater the challenge, the more your powers will be activated, and the greater the satisfaction you will enjoy.