I can't remember when I haven't been telling someone - mostly myself - stories. So I'll stop trying.
I believe stories should be "round" in nature: they should have circles inside of them that complete themselves in some way. They can be a simple circle or one intricately drawn like a snowflake, so long as they complete themselves.
I prefer happy endings because my grandmother taught me a happy story is better to watch when you are feeling sad. I like to make people happy. This makes me happy. Which makes me do more. Which makes people happy... get the circle here?