Social Skills of a Calico

This cat keeps appearing at my door, its green bulging eyes staring me down as a I eat my dinner. My own cat, I've noticed, has no social skills whatsoever. If my cat was a human and wanted to get to know a person, she'd wait outside this person's favourite restaurant and when they leave, she would run up and smell their napkin. For instance, she watches this cat from a bush and then when the cat leaves, she runs up and sniffs the grass. My cat is a pure bread stalker.