"Death and taxes are the only things certain in this world," Ben Franklin is said to have said. setbacks would have been added to his list.

In life, no matter how well-off or well-trained you are, there will be setbacks. People will tell you no. There will be times when you worry you don't have what it takes. Some people get back up while others give up.

There is probably no one better suited to answer this question. The bible of perseverance was written by a University of Pennsylvania psychologist. She explained the differences between those who quit and those who stay the course in a recent post on the TEDIdeas. It was a single word.

Circumstances determine who reaches their goals and who doesn't. It makes sense that people who have less distance to travel are more likely to finish the journey. A person's mindset is an important factor in determining whether they can weather setbacks.

If you're a little hazy on your past, the expression comes from the time of Julius Caesar. Even though the Roman Senate had forbidden him from doing so, the Roman general decided to lead his army across the river. It was not possible to go back. His options were either win or die.

Most of us don't put our lives on the line to chase our dreams. If your business venture doesn't work out, no one will do it for you. If you don't make it in acting, you will live to tell the tale. For maximum grit, you need to metaphorically "cross the Rubicon" and go all-in.

You're fully committed to your goal if you're all in. You don't have to consider the pros and cons of your dreams anymore. She wrote that you are figuring out how to make them a reality. The people who cross the Rubicon are focused on how to chase their goals. When it comes to your level of resilience, changing just that single word is all that matters.

Tim Ferriss' advice to focus on the process you're using to pursue your goals instead of whether or not they are the right goals reminded me of the example set by Duckworth. He says the difference between the two is a small change in language.

The coach of Evander Holyfield once told him that he could be the next Muhammad Ali. Is it possible that you want to do that? He asked his mom. He returned home and said he wanted to do that. The coach agreed. Is that something you want to do? There's a different reason.

Several experts say the difference is profound. There are people with a goal. They don't worry if they're chosen the right path or if they have what it takes. Every day they can take concrete actions to advance and improve. They think about how they should chase their goals, not whether they should chase them.

Those who persist and those who don't are different. Everyone has questions. There are setbacks for everyone. It's how you deal with doubts. The people who give up question their abilities. Those who get back up are focused on their tactics and strategy.