I brought up Dreamscape and The Cell for a specific reason. They are basically the same movie concept. Dreamscape you can enter in someone's dream and influence their real world self however you choose, including killing them. The Cell inducing someone into your own mind influencing your dreams on them etc etc. Also The Matrix, you can bend some rules like gravity, running fast, kung-fu, but don't think about bullet dodging and flying no one can do that...EXCEPT the Deus Ex Machina, he can bend, break and redefine these rules at his will.

One of the characters in the movie says, "If your going to dream, dream big" which was one of two times a character willfully did something "dream-like" to their advantage (the other one was the paradox scene). I think Nolan tried to explain this but I think didn't do so well...you're in a dream, DREAM BIGGER, don't just pull out a bigger gun frickin' nuke that summamabitch sniper.

The ending of Inception: all at once the entire audience groaned out loud.

like if you falling in a dream (the van scene), the nest dream you would be floating(the hotel scene), but wouldn't you be floating in the next nested dream (the snow fortress scene) It would make sense right?

Also, the subconscious of the host dreamer will attack anyone screwing around with reality, like the scene where the "mob" is attacking Ellen Page (Juno) in Leo's dream , in the "van dream" who is attacking them? The dream was hosted by Yusef, the driver of the van, they say it Cillian Murphy's sub conscience, but Yusef (the van driver) is hosting the dream it doesn't make sense to me. (The van scene was hilarious I thought since Yusef had to pee, it rained in the dream; good touch). Then to get deeper into Cillian Murphy sub conscience, then they host into Aurthur (Joseph Gordan Levitt) in the van to get into the hotel, which yet again, they are attacked by Cillian's subconscience. In the hotel, they go to sleep into a dream hosted by Eames (Tom Hardy (who was amazing in Bronson BTW)), to get deeper into Cillian's subconscience and yet again they are attacked by Cillian's troops...again.

Here's an example, which may have holes since I'm talking about computers and not humans: Ok, imagine that there are four computers and you're at one of them, then remote into another computer. Then from that remote connection, remote into another computer. See where I'm going? One computer, into another computer, into another computer...at what point will that forth computer just give out all kinds of information or be influenced to do something else? I know that I'm talking about computers and not humans which can accept influence. This is what I'm mainly stuck on. I guess it is a mechanic.

Cillian's sub conscience was trained to recognize dream intrusion, even if somebody else is the host. After all, what's the point of all of the training if all somebody has to do is pick a different host to defeat the defenses?

Well the entire movie lays out the rules for you as you watch it. One of the rules of a dream is that you don't realize you're dreaming at first, you just arrive in the middle of a situation and go with it, the movie itself starts out the same way, he's on a train, we don't know who this client is or why it's going on, we just go with it. Another one they explained later is that you can turn the dreamer's subconscious against them, Cobb's subconsious is obviously against him in the form of his wife Mal, and explains why those guys were chasing him in Africa. Also at the end his children are wearing the exact same clothes that you always see him dreaming about them wearing, I thought this was the biggest "The entire thing was a dream" hint, the other is that you don't ever actually see his top fall on it's own accord through the movie, he gets interrupted I think every time he uses it? Though I could be mistaken, if it ever falls down, I'd call that a plot hole.

Eric, you raised interesting points, some of which I thought about near the beginning of the movie.

I first thought that maybe everything was a dream when they were bouncing from major city to major city, getting in fights and being chased by men with guns. It was dream-like in that all of that is fantastical compared to our everyday experiences and it was presented to us without much context.

The problem is that those same things are standard movie tropes. So, if I'm supposed to consider those indications that Cobb is dreaming, then all bets are off. I now can't depend on my prior understanding of how American movies work; I have to question everything, even if it's a way that most movies just work.

Take your point that Cobb's children are wearing the same clothes at the end of the movie. That very thing is often a concession movies make to their audience: characters we see only briefly have similar appearances each time so we can immediately recognize who it is. Further, he's probably been on the run for years, and his kids aren't any older. Yet, we make age allowances to movies all the time because we recognize it's difficult to find child actors who look like another child actor plus five years.

I have a difficult time believing Christopher Nolan intended me to think things through like this. On the other hand, Nolan is the most "meta" of all contemporary, popular Hollywood directors, so maybe he did.

In the end when they were trying to plant the inception into the kid, they actually went 4 layers deep. The whole 50 years stuck with is wife layer. That's where he finally got rid of his wife and found Saito. Plus, if you assume that the first layer that he believes is reality is actually a dream, he's now gone at least 5 layers deep, if not more? So 1 day in the "real" layer is like 200+ years in the 5th even though he only seems to spend a few hours at a time there? And he's constantly going in and out of his layers back and forth while dragging pieces of his subconscious (his friends, Saito, the heir) in with him? Sorry, doesn't add up if you assume his "waking" layer is actually a dream as far as I can see.

The fact his kids are wearing the same clothes and move the same way is one of those inconsistencies filmmakers use to ensure there's some doubt as to actually what's going on to leave that question of whether it's reality or not. I can't see how it's anything but reality at the end

Cobb is in his own dream, architected by his father. His father did this so his son would be happy. This could explain how Cobb finally sees his children's faces even if he's in a dream: that memory is his father's, not his.