Everyday English for keeping in mind(with a Rembrandt Gallery)

How come?

How come one person moves forward with one success after another, and yes some are still getting ready?

How come one man goes through crossing one hurdle after anotheraccomplishing his goals while another struggles and gets nowhere?

Rembrandt HARMENSZOON VAN RIJN: Doctor Nicolaes Tulp's Demonstration of the Anatomyof the Arm. 1632.】