Here's the low down on good bacteria. In particular Wolbachia is a bacteria that keeps insects, such as mosquitoes, healthy so the don't carry diseases that they can spread to people.
Biologiest have given a lot of thought to how species evolved different sexes and why. Inés favors the Hurst Hamilton Hypothesis which deals with genetic conflict between the genes of the gametes in the sexual partners.
Memory is unreliable. Inaccuracies are introduced when they are encoded, consolidated and retrieved. And memories can be altered, sometimes substantially.
