Which is your interpretation of Shepard´s dreams on Mass effect 3 ?

The child was stated by Bioware in the artbook I believe to be a representation to all the people Shepard couldn't save no matter what they do. Having a face to attach to that idea hits harder than a mass of people. 'One death is a tragedy, one million is a statistic' kind of thing. They have the mass of people too in the form of the shadows wandering around in the dreams, and to finalize that concept they have lines from your team members who died throughout the games.

It can be interpreted in different ways. I would guess Bioware wanted to say that everyone couldn't be saved. The problem is that I already knew that. I didn't need the dreams to tell me that.

The kid is the only one seen in the whole trilogy. So when he was killed with the rest of the people on the shuttles, it was sad, but it wouldn't be enough to have dreams about him. If anything, my Shepard cared more about A/K who died on Virmire than the kid. Then when the catalyst is shown in the kid form, I just said whatever.

I just headcannon my Shepard is dreaming about being at a Led Zeppelin concert

Bunch of s**te. I was going; wtfh is this crummy sequence. wth is the kid? If Shep has to dream about bad stuff (from stress, etc), it should be someone s/he knew. Disliked the dream sequence so much I wished I could dump it down the clapper when I was playing the game.

I thought the kid was just a representation of the loss of Earth.  His death symbolized the deaths of so many on Earth.  It's in line with all dead teammates having a voice in the dreams.

Curiously, the presence of Shepard himself in the last dream really threw me since I've only ever played with Citadel DLC installed.  I made an assumption that the "Shepard" in the dream was actually the clone, who was dead by this point.  It was pretty recently that my attention was drawn to the fact that it was actually Shepard and not the clone (though I guess either interpretation works with the dlc installed).  In that case, it's foreshadowing Shepard's own probable death, which is what I always assume was BioWare's intention.  (Not my intention, though, since I always save him.)

I have a different interpretation on the dream bop since the Shepard I play is a marine with conscience. Everyone has their own way of looking at things. Everyone has their own Shepards.

Everyone has something that haunts them. Sometimes, it comes back to haunt them again in the future. They would be reminded, they would think of that old event or person / people. They replay the mistakes they made over and over again (sometimes persistently), what they should have done, what they shouldn't have done, decisions they should have made. Shepard is a marine. Every death is imprinted and never forgotten, especially more so since Shepard became an officer. S/he knows what they're getting into or they wouldn't have signed up. An action, a command that could result in death is felt more personally. 

The wound that cuts the deepest is always the one that floats to the fore. Since there is little known of Shepard's military history, we could only go on what we knew from ME 1. The death on Virmire. S/he was forced to leave the officer and / Salarian squad behind. S/he made the decision, there was nothing else they could do. We go to ME 3, s/he could only watch helplessly as the Reaper destroyed the rescue shuttles. Again, Shepard could do nothing.

The nightmares make sense. Shepard is experiencing a lot of stress. Cumulative since ME 1. Deep down, s/he felt vulnerable, helpless. Deep down, they didn't think the war could be won. They knew millions were going to die and they could do nothing.

What doesn't make sense is the kid. I would have accepted it better if Ash / Kaidan / Salarian squad (and companions who died in ME 2) were also in the dream sequence. Why not? Don't all of them hold the same aspect? Even before that kid showed up at the end, in the first PT, I was going; wtf are you? I know you're supposed to be Shepard's guilt, but why only you? There're others. There should be others. If they could bloody add in the voices of the Virmire officers, then they could / should put them in there and have them confront Shepard.

My itty bitty minus point one one cent. End of line. 

And even that can be justified by a Paragon who makes the military command decision to stop Sovereign at all costs. That's how my first playthrough went.

Suspicious Reaper intervention to exploit overt or latent negative feelings of Shepard, for the purpose of guiding him towards his end. The child represents something that only a monster could ignore (though Shepard can be such a monster that it makes total sense for him to struggle against this messaging; but usually he's not RPed that way), while also having that level of annoyance about the kid that only the utterly naive could ignore (though Shepard can be so trusting that he'll just go right along with whatever happens to him as long as it looks good; but usually he's not RPed that way... or at least not that much).

Weird dreams be weird dreams. Whatever happened, he made it to the beam.

Shepard wants to sleep with his mum (resp. her dad)