what if all of the dreams here where put down in a journal in chronological order. we may just find that a good portion of them tie into each other.

That can be your project.

yeah i'll get done in 30 years

I think this just emphasizes the fact that there are common themes in everyone's unconscious.

We all have the same basic drives/fears, and people from similar cultures are going to represent them in similar ways in their dreams.

Related articles on the subject include:

Dream Archetypes

Collective Unconscious

The above 2 involve the work of Jung.

The Evolutionary Theory of Dreams

Basically, a theory in evolutionary biology that we evolved to have certain types of dreams to teach us how to cope in difficult situations in waking life. Since we humans all started out living in the same environment - before we expanded outward to populate the globe and developed different lifestyles and cultures - we share similar dreams.

Discussions of the more common dream themes can be found here: Dream Themes