1. I myself (possessive pronoun + self)
2. You yourself (possessive pronoun + self)
3. He himself (not possessive pronoun + self)
4. She herself (possessive pronoun + self)
5. It itself (possessive pronoun + self)

6. We ourselves (possessive pronoun + selves)
7. You yourselves (possessive pronoun + selves)
8. They themselves (not possesive pronoun + selves)

Whence this irregularity?