Technically they are equal, they just happened to be born somewhere different. So it should be fair, right?
That kid when he grows up might indeed feel weird about all the undeserved money...
Are you serious? How is taking money from one person who never worked for it and giving it to another person who never worked for it going to make one feel self-conscious and sympathetic to the other?
Edit: To directly answer your question, It's not about being sympathetic to the other. They just didn't deserve the money. You "feel" they envy of other people and ask yourself why you and not somebody else. At least if you were the legitimate heir you knew that your family earned it somehow...