At first i would like to say Thanks for asking! I havent thought of this for a while, ...
I play EU for so many reasons that i have to generalize my answer. Get ready to dip into consciousness philosophy!
EU augments my reality as the embodied consciousness that i am as a human. It expands my possibilities to interact with the world and dramatically increases speed and range of my interactions, read cause and effect, to a worldwide scale.
Compared to the real world EU is like a cradle. The baby inside the cradle is my very own conciousness and it has an avatar in the virtual reality of EU amongst many other avatars of other consciousnesses (of the real world), that i can interact with. Because of that virtual avatar my senso-motoric real world embodiment plays a minor role, in the virtual world. Its trained (or not) to be an interface to the interface of my computer. Thats all about it. We make games out of this to find out whos interface to interface relation works best,...
they say thats all about it. And just because we are making games in the virtual world EU is a cradle, a place where you can try out stunts or get into confrontation, still falling soft maybe losing 60 Bucks not 600K Bucks (or your life) like in the real world, if you tried the stunt there.
... So theres a second level beyond the consciousness, my augmented consciousness embodied by my virtual world avatar. It interacts inside a world designed in patterns that a real life consciousness is familiar with, even though cause and effect of the real world and the virtual world differs a whole lot. This similarity in patterns AND differences of cause/effect is the treasure chest. Just because the ingame patterns are specially desgined to fit to what i am (read my cosciousness) familiar with, they can be useful as a trainer for my real life skills interacting with these patterns.