Can you assemble a laptop

Yesterday, I had the privilege of opening and upgrading the RAM of a P4 computer a relative had assembled from scratch. Thats when this weird thought occurred to me: Why can't I assemble a laptop in a manner similar to a standard desktop computer? What exactly stops the assembling of a laptop from scratch?

My search let me to this post which nicely explains that this is not possible due to lack of standards in the laptop world. For instance, there is the Atx standard which is universal for desktop motherboards. A poster proposes a hypothetical Ltx standard for laptops:

Let's break LTX down into a few sizes, for displays. your basic LTX case comes with a power supply, a display, and cords. the display size dictates the exact LTX size. so, a 14 inch display would be LTX-14. tentatively, lets start with -8, -14, -17, and -22.

LTX-14 motherboards would be required to fit into an LTX-17, but not the other way around for obvious reasons. if you wanted to (for whatever reason), you could put something together using standard components that is only slightly more expensive than a current netbook, and has a 22 inch display. put a LTX-9 ATOM motherboard into a LTX-22 case.

MicroLTX would be similar, but not have space for a separate laptop video card (o yes, we are standardizing laptop video cards, too) and perhaps top off at two RAM slots. MicroLTX motherboards fit into LTX cases, but not the other way around.

all connectors pertaining to the display, power, etc, would be identical. individual case OEM's can use different hinges to attach the display to the base and whatnot, but the wiring all needs to be identical.

Leaving aside the topic of standards, is it possible for an average John Doe like me to assemble a laptop from scratch in a cost effective manner? If yes, then how do I go about it?