Atticus says that you never really understand a person " until you climb into his skin and walk around in it". What does this this mean? Is it an easy thing for Scout to learn?

"You never really understand a person until you consider things from his point of view...until you climb into his skin and walk around in it."

Scout comes home from school in a bad mood. Atticus imparts some of his special wisdom on to Scout. Atticus is very good at observing things from different points of view. He does this as a lawyer and as a human being. Scout is just learning this very advanced human trait of empathy. Most people never really learn this but Scout is well on her way. By the end of the novel, she has caught on. Instead of screaming or acting shocked at Boo Radley, she gives him a friendly smile and simply says, "Hey Boo."