Why did Columbus go in search of India not around Africa, but west across the Atlantic Ocean?

The whole point is that Columbus did not have maps (which the Portuguese had) in order to sail across Africa. He also mistakenly hoped that the circumference of the earth is not so large and, if you sail to the west, you can reach India. In general, Columbus strove to make an expedition as soon as possible in order to be the first to open the way to India. Nevertheless, when Columbus saw land in 1492, he mistakenly took these lands for India, even the population called them Indians. Over time, it turned out that Columbus was mistaken and in fact discovered a new mainland, and not a path to India.