Success never comes down to just one thing. Intelligence, talent, experience, education, and even luck all play their part. But often what separates success from failure is perseverance. Keep going and you still have a chance to succeed; quit, and all hope of success is lost.

Even so, when things get difficult and the odds of success seem bleak, doubt naturally sets in, and slowly -- although sometimes very quickly -- drains away your willpower, determination, and motivation.

And then you quit.

Which means you failed. (At least in this instance.)

That's why most people try to push away self-doubt. They know that confidence is key. So they put their blinders on, stay positive, stay focused...until that moment when a challenge straw breaks the confidence camel's back, and doubt, as it inevitably does when you try to accomplish something difficult, creeps in.

So how do you avoid self-doubt?

You don't.

Doubt is normal. Doubt is part of the process. We all question whether we will actually accomplish something difficult while we're doing it.

As retired Navy SEAL Sean Haggerty told me, there's a big difference between doubt and failure:

Don't confuse doubting yourself with accepting failure.

The best thing I did was to decide that I was going to go to the absolute extreme, even if I doubted myself. I basically told myself that no matter what, I wouldn't quit. I doubted myself a number of times, but then I put away and thought, "If I fail, I fail...but what I will never do is quit."

That attitude pushes you past a limit you think you have...but you really don't.

Instead, doubt is just a sign of difficulty. Doubt doesn't mean you can't do something or won't do something. Doubt just means you need to figure out a way to keep going.

One way, especially when you feel overwhelmed, is to keep your world small. According to Andy Stumpf, a retired Navy SEAL and SEAL instructor, there are two ways to approach the BUD/S (SEAL training) program:

  • One is to see it as a 180-day program, and by extension to see Hell Week -- the defining event of the program -- as a five-day ordeal. (Hell Week typically starts Sunday evening and ends on Friday afternoon; candidates get about two hours of sleep on Wednesday.)
  • The other is to just think about your next meal.

They have to feed you every six hours. So if I can stack six hours on six hours on six hours, and just focus on getting to the next meal, it doesn't make matter how much I'm in pain, doesn't matter how cold I am. If I can just get to the next meal, get a mental reprieve and mental reset, then I can go on.

If you can apply that resilience to setting and approaching your goals from digestible perspectives, you can accomplish an insane amount.

When you're in the middle of Hell Week and you're cold, exhausted, and sleep-deprived, making it through the next few days seems impossible. It's too long. Too daunting. Too overwhelming. No amount of self-talk can overcome that level of doubt.

Stumpf knew that. He knew he couldn't imagine making it through five days.

But he could imagine making it to his next meal, which turned a major doubt into a small doubt.

Doubt was just a sign he needed to figure out a way to keep going. And he did.

See self-doubt not as a sign that you should quit, but as a natural part of the process. See self-doubt as a sign that you need to adapt, innovate, or optimize. Not as a sign that you should consider quitting, but as an early warning sign indicating it's time to figure out a way to keep going before those doubts grow so large that you do quit.

Doubting yourself? That just means you're trying to accomplish something difficult.

So see doubt as a good thing, because doubt is a natural step on the road to success.