It is said that once Ptolemy (the king of Egypt, who ruled between 323 and 282 BC and became the founder of the famous Ptolemaic dynasty), decided to get serious math. Fortunately, he lived at the same time as the greatest ancient Greek mathematician Euclid.
Having come to the wise man, the king said that he wanted to learn geometry quickly, easily and as simply as possible.
Not at a loss, Euclid answered: "There is no royal road to mathematics"!
It is from this interesting fact that this expression has gone, which is paraphrasing differently.