Why is the legend of sargon i considered a "rags to riches" story?

The answer to this question is a child that was abandoned at birth rose to become a great King

Known as Sargon of arkad, he was the First rule of the semitic speaking arkadian empire. He was believed to be an illegitimate sone of a priestess. There is a striking similarity between his story and that of Moses of the bible, which makes the whole legend confusing.