Regret is a funny thing.

When we think about something major we want to do -- start a business, change careers, move, etc. -- we think about how much we'll regret making that decision if it doesn't work out. We're afraid we'll regret doing what we want to do. The path seems uncertain, the future unpredictable. 

But when we look back, what we regret are the things we didn't do: the business we didn't start, the career change we didn't make, the move we didn't make. We don't usually regret the things we did, because even if we made a huge mistake, we can fix it. We regret the things we didn't do. We regret the times we didn't take a chance on ourselves.

"What does your heart say?"

The reasoning is simple: Four of the worst words you can say are, "If I had only ... "

Think of all the things you've wanted to do but never have. What did you do instead? If you're like me, you can't recall. All that time is gone, and whatever I did instead wasn't even worth remembering. Think about something you dreamed of doing five or 10 years ago but didn't do -- and think about how good you'd be today at that thing if you had. Think about all the time you wasted and can never get back. 

Sure, the work might have been hard. Sure, the work might have been painful. But the work will be a lot less painful than someday thinking back about what will never be.

The same is true with wanting to move to another city or state or country. Familiarity creates comfort. But comfort is often the enemy of improvement.

If you have a great opportunity and the only thing holding you back is the thought of moving, move. If you want to be closer to family or friends and the only thing holding you back is the thought of moving, move. If you want to be closer to people who think and feel and act like you, move.

Don't worry; you'll soon find cool new places to hang out. You'll soon develop new routines. You'll soon make new friends. When the fear of moving is the only thing holding you back, move. You'll meet cool new people, do cool new things, and gain a cool new perspective on your life.

Besides: Thomas Wolfe was wrong. If it doesn't work out, you can go home again. (Even if just for a couple of hours.)

Still not convinced that following your heart is the right approach where major personal decisions are concerned? Here's Bezos:

I went to my boss at the time and I really liked my job, and I told my boss I was going to start doing this thing, do an internet bookstore and I had already told my wife and she's like, "Great, let's go," and I said to my boss and he's like, '"I think this is a good idea, but I think this would be an even better idea for somebody that didn't already have a good job." 

For me, the right way to make that kind of very personal decision, because those decisions are personal, they're not like data-driven business decisions. They are, "What does your heart say?"

And for me, the best way to think about it was to project myself forward to age 80 and say, "Look, when I'm 80 years old, I want to have minimized the number of regrets that I have." I don't want to be 80 years old and in a quiet moment of reflection, thinking back over my life, and cataloguing a bunch of major regrets.

In most cases our biggest regrets turn out to be acts of omission. It's paths not taken and they haunt us. We wonder what would have happened. I knew that when I'm 80, I would never regret trying this thing (quitting a good job to start Amazon) that I was super excited about and it failing.

If it failed, fine. I would be very proud of the fact when I'm 80 that I tried. And I also knew that it would always haunt me if I didn't try. And so that would be a regret, it would be 100 percent chance of regret if I didn't try and basically a 0 percent chance of regret if I tried and failed. That's a useful metric for any important life decision.

Looking back, that's easy for Bezos to say. But it wasn't at the time. Deciding to follow his heart took courage.

But being brave doesn't mean you aren't afraid -- in fact, the opposite is true. Courage without thought or meaning is simply recklessness. Brave people aren't fearless; they've simply found something that matters more to them than fear.

Say you're scared to start a business. Find a reason that means more: creating a better future for your family, wanting to make a real difference, or hoping for a more rewarding and fulfilling life.

Once you find a greater meaning, you also find courage. See fear not as something to shrink from but as something to overcome -- because that's all it is.

And see regret not as something to avoid someday feeling because you tried and failed, but instead to avoid someday feeling because you never tried at all.