Are you your characters?

A fiction writer creates characters, so this is a natural question to ask such an author. I guess my answer if asked it would be ambivalent: Maybe.

Probably every author puts a bit of themselves into some characters they create, but most authors are observers of human nature and are more likely to use what they see and hear into their characters. (Observations of ETs are a bit more difficult, but they might have some human-like characteristics.)

A secondary but related question is: Which of your...