A more fitting analogy would be if right now all the LEGO factories would stop producing, and you start building the largest LEGO building imaginable from scratch. You might be able to get all the pieces together at one point, but the Sun would explode first. (added for dramatic effect)
The difficulity is getting the pieces from all the places in the world. Even from under the sea.
The picture is short a few pieces?
A more fitting analogy would be if right now all the LEGO factories would stop producing, and you start building the largest LEGO building imaginable from scratch. You might be able to get all the pieces together at one point, but the Sun would explode first. (added for dramatic effect) The difficulity is getting the pieces from all the places in the world. Even from under the sea.