I really think there is something to the Ethan Hawke scene

You're going to need more substance than that, or people will just turn the argument around on you.

The fact that your theory makes you depressed is a sign you've got something wrong.

It's the scene where he is talking about the experiment with the crosswords, right? A crossword which was already solved by another human being gets solved easier a second time. That means an idea which was already thought by someone gets into the collective consciousness and another one can have this idea then more easily.

Sorry to say, that's just plain wrong. This experiment has been done and the theory was falsified.

Speaking purely from my own perspective (who elses?) I'd have to say I don't buy the idea. We do all clearly share common threads, many of us think alike, we can think the same thing at the same moment as someone on the opposite side of the planet, but I don't think these are causal.

Rather than being something that physically connects our subconscious with other people's in real-time, we have animal instincts many of which are left-overs from our earlier days on earth. Like the way many different cultures managed to start different types of religions at roughly the same time as a way of coping with our self-aware existences. The fact that none of these religions yielded any of the same deities proves (to me) that, first none of them have any objective truth and second, as is relevant in this case, that the collective unconscious doesn't really exist.

Obviously I take a very Darwinian approach to these issues. I personally wouldn't put any faith in any theories that could be interpreted as being in any way paranormal, as I think this may.

Don't worry man. In 200-300 years religion will be a minority. United States being one of the last countries to let go of it. With advancement in medicine and when we finally perfect AI...our thinking levels will be more logical than primitive as they have been. There are scientists, theorist, and authors who all believe that we will integrate ourselves with machines ( AI nano machines ) in the next 50 years.

With AI accelerating our thinking and keeping out bodies in top form we'll have figured out so much more than what we know now. Most likely dropping religion as it is illogical banter and finding ways of bettering our species as a whole. I find ingratiation of machines as our evolution. As waiting for it naturally will take to long and we'll most likely destroy ourselves without AI's help.

As someone who was originally trained as a psychologist, I think that Carl Jung came closest to helping us visualize the concept of the collective unconscious. But many amateur/pop psychologists misinterpret the meaning of this concept.

The best way to think about a collective unconscious is via evolutionary theory. The collective unconscious is best thought of as a collection of genetically programmed readinesses to respond in a fairly predictable way to stimuli in the world, even when we first encounter those stimuli.

A simple example is our natural fear of snakes. This fear entered our collective unconscious because enough of our ancestors reacted with fear at the sight of a snake, and these individuals were thus more likely to survive and pass along that readiness to respond in that manner.

But we are social animals; so the collective conscious appears to extend into the social realm as well. This is why we speak of archetypes such as the Hero, the Wise Old Man, etc. However, the more abstract and social the archetypes, the more they are likely to be the result of cultural transmission rather than the result of biological natural selection. But even here, there is probably a Darwinian/biological natural selection element going on; because those who respond appropriately to a social archetype may be more likely to be socially acceptable to others, and thus may have a higher probability of procreating and passing along those elements of the social collective unconscious to their offspring.

But the Lamarckian idea that learned behaviors can be passed along via evolution is not correct. So that theory does not lend itself to a notion of the collective unconscious, which is, as I said above, simply an evolutionarily based readiness to respond to particular types of stimuli in particular ways that are fairly standard/predictable.

And because humans have the capacity for rich, abstract symbolism, some of these archetypes can be rather elaborate. Here's a decent summary of some standard archetypes:
http://www.billstifler.org/HUM2130/files/4D-006-archetypes.htm

I like that. I wish there were more of you.