Why is it so difficult to use a "true mirror" as a mirror This Youtube video shows what a "true mirror" is: https://www.youtube.com/watch?v=ZSxCZCy5Wsk

In short, when you look into a true mirror you look at yourself (among other things) as you really are, instead of as a mirror image. That is what looking at real time video recording feels like.

But as anyone ever tried shaving or doing their makeup using a live video can tell, a true mirror makes you clumsy, to say the least. From my own experience, I find myself constantly confuse both left-right and front-back in such a case, which is interesting because a true image is just a mirror image that reverses left-right and front-back. So it seems to me some part of my brain in some sense recognizes my true image as a mirror image, and summons whatever pertinent mirror image circuits to automatically take on from there. Any other thoughts on how to explain this difficulty?

Think about this: suppose a person grows up never seeing a mirror reflection, will he be able to use a mirror for the first time? will he not be better off with a "true mirror" than with a mirror? If he grows up using true mirrors, will he be as clumsy with mirrors as we are with true mirrors? We feel natural and at ease dealing with mirror images. Is this just the result of practice and experience? I'm curious if a true mirror will become as natural as a mirror if one uses it for long enough.
This answer supports the comment by Krysta that we are simply used to the mirrors we have and could just as easily learn to use a "true mirror".

In 1950, Theodor Erismann and Ivo Kohler performed a famous self-experiment in Innsbruck, Austria. Kohler wore a pair of glasses that turned his view of the world upside down continually for 124 days (sic). After about 8 days his perception had adapted and he was able to ride a bike or paint just like before.

The image below shows Kohler wearing the glasses:



Here is the original documentary movie created by the two researchers (in German) on the website of the Center for the History of Psychology at the University of Würzburg, Germany: http://www.awz.uni-wuerzburg.de/archiv/film_foto_tonarchiv/filmdokumente/th_erismann_ikohler/die_umkehrbrille_und_das_aufrechte_sehen/

Here is an article from the German Wikipedia describing the glasses and showing an image of a current (self-built) model: http://de.wikipedia.org/wiki/Umkehrbrille I don't know what this "Umkehrbrille" ("turn around glasses") are called in English.