Is there more to dog psychology than we as human beings can ever know?

Probably. Dogs are a different species, with different instincts, etc. etc.

"Psychology" is a bogus word. It means the study of the way people, or in this case dogs, think. But nobody has any way to know how any other creature thinks. Psychologists observe behavior and pretend to know something when they are only guessing.

Is there more to human psychology than we dogs know :P Seriously yes there probably is, in the wider definition of the term.