Good humor is a tonic for mind and body. It is the best antidote for anxiety and depression. It is a business asset. It attracts and keeps friends. It lightens human burdens. It is the direct route to serenity and contentment.

Treating everything seriously is a sure-fire recipe for frustration and depression, particularly when you repeatedly get hit with one obstacle after another with no chance to catch your breath. Negative thoughts can sprout in even the most positive minds, but it’s your choice whether you nurture them or pull them out.

When I was struggling to grow one of my businesses, my laptop broke down. I not only had to buy a new computer to be able to continue working, but also pay a steep fee to have my data recovered (I’ve since learned how important regular data backup is!).

To make matters worse, all of that happened while I was deep in debt. I tried to keep my spirits high, but make no mistake — it was one of the darkest, most hopeless periods of my life. Still, if it weren’t for at least trying to be positive about the future, I’m sure I would have had a challenging time sticking to the business that had landed me in so much trouble.

I’m not going to sugarcoat it. You will face seemingly hopeless situations and your self-discipline will be tested on numerous occasions. How will you maintain good spirits despite the negative circumstances? What are your most effective techniques to make yourself feel better?

I strongly suggest creating a list of simple ways you can improve your mood that you’ll be able to turn to when you find yourself in a distressing situation.

Take up one idea. Make that one idea your life — think of it, dream of it, live on that idea. Let the brain, muscles, nerves, every part of your body, be full of that idea, and just leave every other idea alone. This is the way to success.

While flawless, 100% focus on a single idea is close to impossible for a modern human being, there’s a lot you can gain from focusing as much as you can on just one goal. In fact, I consider it so important that I wrote an entire book about it titled The Ultimate Focus Strategy.

There are two primary benefits of making a single idea your life.

The first one is that limiting your focus to a single thing requires a great deal of self-discipline, which subsequently makes it an excellent exercise in cultivating self-control. I’ve acquired a lot of self-discipline (and finally achieved my goal of building a successful business) thanks to limiting my focus to one business model. Sticking to one thing has taught me the value of patience, dedication, and made me realize how powerful small (and consistent) improvements can be over the long term.

The second benefit of extreme focus is that by centering your life around the one most important endeavor, you’ll be more likely to reach it than if you were to spread your attention thin.

You have higher chances of implementing new nutritional habits and losing 20 pounds (or 10 kilos) in the next six months than trying to lose weight while also implementing a new workout routine, building a side business, fighting against your fear of public speaking, saving money for an emergency fund, and learning a foreign language.

If self-discipline is a resource that you can deplete (scientists are still trying to figure it out), it makes sense to spend it judiciously, starting with your most important goal.