How do you use introspect in a sentence?

Teenagers are all but required to be introspective, as part of growing up is figuring out who you are.

No one at the company guessed that their quiet, introspective bookkeeper was secretly embezzling a sizable chunk of their net profits, and that was part of the fun for him.

He has never been an introspective person, so I don't know how he's going to write a memoir without substantial help from a ghostwriter.