Know Yourself. Face Your Fear. Follow Your Heart. Regret is the most tragic thing in life. Here's how to avoid looking back, shaking your head, and saying, 'Wish I knew then what I know now.'

There's one thing I can absolutely guarantee will happen to you at some point in your life. You will look back and say, "Wish I knew then what I know now."

Don't get me wrong. I'm not the kind of guy that does that a lot. Long ago, a friend told me, "Never look back. You can go crazy wondering what could have been." I've never forgotten his advice and, sure enough, I rarely look back.

But here's the thing: There's a good reason why I don't have to. For whatever reason, I've always followed the path that seemed right to me. I took risks when I needed to. And I didn't let fear get in my way. Sure, I've spent a good part of my life terrified, but I highly recommend it.

That said, there have been moments when I regretted what I'd done or, more frequently, what I didn't do. To help you minimize those bitter moments, here's some advice for those who are just getting started.

Observe people. You see a crazy number of laundry lists of attributes and behaviors that successful people are supposed to have, but if I had to pick one – just one thing that made all the difference – it's observing people. Everything in business is about people. If you get people, you'll probably kill it out there.

Related: Searching for Wisdom? Search Yourself.

Take the first step in the right direction. No, I'm not trying to be absurd. Of course you can't know in advance what the right direction is. But if an opportunity arises and you don't take that first step, if you don't go for it, if you don't say, "OK, let's rock," I can absolutely guarantee you'll never find the right direction. Learn to say yes ... a lot. If it scares you, all the more reason.

Build relationships. If you're a people person, then friendships and relationships come naturally to you. If not, it wouldn't hurt for you to get to work on that a bit. No, I'm not saying you can't be successful if you're introverted. Of course you can. All I know is, life is like a tree that branches like crazy, and each branch usually involves a person.

Find a way to do what you find exciting. The hands-down best piece of advice I ever got was when someone told me that digital technology was going to become huge. That was in 1977. I don't know why, but it sounded exciting. And following that path was the hands-down smartest thing I ever did. If it sounds exciting to you, that's your heart telling you something. Listen. And find a way to do it.

Related: The Only 9 Things You Need to Know About Selling

Be geographically mobile. Most of the people I knew growing up that never left, never went anywhere in life. If that was their choice, fine. But I bet many would do it differently if they could do it over. Steve Jobs grew up in Silicon Valley. That was the luck of the draw. Most of us aren't that lucky. Don't let geographic boundaries stand in the way of your future.

Try to save money for after college. I speak with a lot of college grads that took out loans, had all sorts of side jobs, and when they finally graduated, ran out of steam … meaning money. If you're a hot software developer, companies may fly you around and roll out the red carpet. But the rest of you have to pay your own way to interview, relocate, get an advanced degree, or maybe even start your own company.

If it isn't working, try something different. It's not always easy to know that what you're doing isn't working, but let's put it this way. If you're miserable and you would rather be anywhere doing anything but where you are doing what you're doing, it's safe to say it's time for a change. Don't wait. If you're not sure, trust your gut.

Regret is the most tragic thing in life. The best way to avoid it is to know yourself, face your fear and follow your heart.

Related: Want to be Successful? Learn How to Manage.