Henry Ford said, “Whether you think you can or you think you can’t — you’re right.” I have been thinking a lot about that quote lately while studying human effort. When thinking about things that one can do in life it is easy to think about everything that stands in the way.

Our minds are good at putting roadblocks in our path. They are our minds way of keeping us safe from harm and disappointment. Yet, most of the roadblocks aren’t real. They are imaginary scenarios based on faulty perceptions of the world. But, there are things beyond our control that can snatch “victory” from our grasp in an instant. However, effort is the one thing always within our control. No matter the situation or task, the amount of effort we put into it reveals our commitment and our willingness to persevere.

I have written before about the Navy Seal 40% rule. The rule states that when your mind starts telling you you’re done, you have only used 40% of your capacity. So when you think you’re finished, you are not. In my experience, many individuals—I am guilty of this—quit well before they hit their 40% mark. Going to and beyond the 40% mark is a sign of mental toughness.

Angela Duckworth in her book Grit talks about mental toughness and it’s impact on one’s life. She makes the case that anyone can develop mental toughness no matter their stage in life. Many top athletes cite mental attitude as the biggest factor in their success. Yes, they put in hours building their strength, but the real gains happened when they were mentally prepared.

Every time someone breaks a world record, the pundits question if it can ever be beaten. For example, when Roger Bannister broke the 4-minute mile mark, people thought beating his time was physically impossible. Yet, the current record for the mile is 3:43, 16 seconds faster. Scientists have yet to uncover the limit of human potential. The depth’s of our mental and physical abilities are unknown. But, every once in a while we get a glimpse of the impossible becoming possible.

In 2013, 16-year-old Hannah Smith was outside on the family farm with her 14-year-old sister when they heard their father cry for help. While using a tractor to pull a stump out, the tractor flipped over and landed on top of him, with the steering wheel crushing his chest. Immediately the girls sprang into action, calling 911 then starting to try and dig him out. After several minutes without progress, Hannah decided to try lifting the one-ton tractor using two-by-sixes and a cinder block. When that didn’t work, she felt the only option was to pick it up and move it. She told her sister to grab one front wheel while she grabbed the other. The first few tries, nothing happened. Then on the next try, with tears streaming down their faces, it moved an inch. Thrilled, they kept at it. Inch by inch they moved it about three feet and got the steering wheel off their dad’s chest.

The impossible became possible. Too many dreams die because they are thought to be impossible. And, that is where the wisdom in Ford’s statement lies. Far too often, we don’t think we are smart enough, or strong enough. Yet, nothing could be further from the truth. The cliche that every journey begins with a single step is true. Achieving the impossible begins with a single step. Then another and another, each one building on the previous until something amazing happens. It always does.