The whole "its no different from a big display in front of you" argument is ignorance on a whole new level, or at the very least denial.
Since some of you seem to be really struggling with understanding the difference, here.
A fixed display is 2D, both eyes see the same image.
A 3D display is 3D, both eyes see a separate image with a fraction of delay as the display itself alternates between left eye and right eye, but the screen is a fixed point in space with a fixed size, the only user input is the controller, has limited manual focal control because of the fixed nature, thus often feels like paralax layering rather than true 3D.
A HMD places a different image in front of each eye at the SAME TIME, because of the proximity from the eye (at the natural minimum focal length) you are given a full focal range so the 3D gives you full range depth and the ability to *focus* on elements as you do in real life, this is combined with sensors both head mounted and external to track both your heads movement and the point in space where your head is, to control your view in terms of looking around the virtual world and adjusting your point in space relative to the location of your head, which greatly increases the immersion and provides a direct link between the full range focal depth and the players natural movement.
So seriously, when you say "it's no different from a big screen, its just right next to your eyes" what you are essentially saying is "I don't have a clue what I am talking about".