As the Ottoman Empire had conquered the region of the previous Byzantine Empire, the Silk Road lost its use. Now, people in Europe had to come up with new trading routes: the ocean routes, in order to trade with Asia.
Yes, the problem was that traveling from Europe to Asia by sailing was insane (tough) at that time, because they had to go around Africa, which required tons of traveling time.
It takes a whole year to get that piece of spice!!! I’m done with it!!!
Now the story flows as you already know. Though he actually could not arrive in Asia, he ‘discovered’ a new continent: America. Here is some free advice, thinking flexibly may be hard due to lots of obstacles that impede you from doing what you want. But it is one of the best ways you can succeed in your life!
Now, here it comes, ‘Christopher Columbus’.
And came up with a brilliant idea, which is a corollary to us now.
If the Earth is a sphere, we’ll be able to reach Asia if we go to the West!
Well… His idea was quite innovative and somewhat perceived as out of senses, since the Earth was thought to be a cube due to lack of research; also because the Roman Catholic had oppressed who insisted the Earth is a sphere. People thought they'd encounter a steep cliff, and a monster waiting for them, if they sailed to the West.
He presented his plan to officials in Portugal and England, but it wasn’t until 1492 that he found a sympathetic audience: the Spanish monarchs Ferdinand of Aragon and Isabella of Castile. Then he was able to be subsisted by the Spanish monarchs and jumped into his journey without any hesitation.