I'd been living a healthy life for while, and kept toying with the idea of being vegan. But whenever I thought about it, I would get stuck how I'd manage certain situations that might pop up.

Business dinners at steak restaurants, travel, my son's birthday, when he'd want me to have a piece of cake with him. You name it, I was worried about what I'd do when faced with a scenario like these, and would keep talking myself out of making the switch.

One night while reading the autobiography of a vegan ultra-endurance athlete named Rich Roll, a brilliant notion struck me.

I said out loud,

I can do it just tomorrow. You can do anything for a day. I'll do a day.

I realized that all these what-if moments were of the future, and not immediate, and that there was no reason not to at least give it a try.

So I woke up the next morning and just made the choice to eat vegan that day.

It was actually really easy. Much easier than I had thought it would be.

So I woke up the next day, and said, "I can do a day today, too." That was nearly three years ago.

I haven't been 100 percent vegan 100 percent of the time, but anytime I've strayed, I looked at why, learned from it, and then committed to making a new set of better choices the next day.

This isn't just about being vegan. The simplicity and power of the idea of committing to do what you have to do in one particular day without fear of what might happen later was so freeing. It allowed me to do something I thought I could not do.

I started to apply the same approach to many more "impossible" challenges I had never even started, like running a marathon, taking on a new job at a very senior level in a function I had no experience in, or working for a terrible boss. It's also how I dealt with nearly losing my wife to a chronic illness, and how we deal with that illness today. Of course there are tough moments, but we are not facing all of them at once right now.

If you look out from today at all of the difficulties you may face, you can very quickly shut down and never even attempt anything you want to achieve. But when you are free from that weight, and you face only as much as you will face today, everything becomes far more manageable.

The idea was so powerful, it became the name of my first book, Do a Day. It's also the approach I used when tackling writing the book. Each day, I did the work I needed to do that day to get me closer to publishing, regardless of how much still was left to do.

So, you may not be interested in becoming vegan, but surely you face something in life that seems like too much as you look out at all of it that you see in front of you.

Turn your gaze a little closer, and go get it.