Imagine you lived decades ago, long before information was readily available on a handheld device. Perhaps even long before televisions or radios.

Imagine at that time your job was that of a fisherman, and you were working far off shore, where the only thing visible in any direction was the straight line marrying the deep indigo blue of the ocean with the pale blue softness of the sky.

Or imagine you were a farmer on the broad expanse of the open plains, and you were working your fields under the calm, blue, cloud-less sky of summer.

Now imagine that as you work, the sky begins to darken, as if clouds were slowly obscuring the sun. But there were no clouds, and the darkness is different than you have experienced before.

Shadows started taking on a strange and alien appearance on the ground. The familiar yet mistimed sounds of dusk resonated all around you. The temperature drops by 15 to 20 degrees.

It is still too bright to look into the sky, but all around you, the sky takes on an eerie feel of nightfall, and the sun almost appears to be extinguishing like a fire running out of fuel.

As you start to be consumed by feelings of confusion and dread, the day suddenly blacks out completely — with the exception of a beautiful, glowing corona with a solid black center visible where the sun once was located. All around, you see planets and bright stars and life feels completely different.

This unique and stunning profundity that a total solar eclipse brought to generations before is not lost on the fact that we can now predict it. It is what has cause experienced eclipse viewers to say that a total solar eclipse is one of the most spiritual experiences of a lifetime — and why everyone should see one.

Why The Great American Eclipse Is Unique

While solar eclipses are not rare — one happens somewhere on the globe about once every 18 months — they are typically only viewable by less than 0.5% of earth’s surface and only about 26 percent are total eclipses (the others are partial or annular).

And, if you want to wait around for the next total solar eclipse to pass over you, you could be waiting up to 400 years.

This is why the eclipse of 2017 (August 21, 2017) is an absolutely unique and once in a lifetime event. First, it will be a total solar eclipse, allowing those viewing it in the area of totality to see the solar corona in a black, night sky.

It will also be traveling over the entirety of the US, from Oregon to South Carolina, and only visible in the US (which is why many are calling it “the Great American Eclipse“). The last time an eclipse traveled over the entire US was 99 years ago.

And if you are wondering about the best way to view the eclipse, allow me to share my easy, seven-step guide.

  1. Identify the best places to view the total eclipse.
  2. Monitor the weather.
  3. Take a personal day at work (or call in sick).
  4. Go to place.
  5. Bring eye protection and a lawn chair.
  6. Look up.
  7. Have your life changed forever.

If you will be missing the solar eclipse of 2017, there will be at least two more this century (2024 and 2045). My prediction is that once you see the upcoming eclipse — and become an umbraphile (eclipse chaser) — you will be at those too.

Absolutely cannot catch it in person? No problem, National Geographic has you covered.

The opinions expressed here by Inc.com columnists are their own, not those of Inc.com.