Is it truly possible to achieve total ‘immersion’ in a game world?

Even if the player is intimately familiar with the fictional universe in which they play they are still at the mercy of their real world personality and learning.

Over a Terranova they raise an interesting point about ‘symbols in virtual worlds’ which illustrates that each player bring their own framework for decoding images within a game. WoW little red crosses to indicate the first aid skill in use, but why would such a symbol be relevant to any one of the races in Azeroth and beyond?

These crosses are not meant to remind your night elf of St Johns Ambulance, is it? It is meant to help your western 21st century player identify the skill. Because our game hours represent such a miniscule percentage of our actual lives (even for hardcore gamers) it is necessary for us to bring our own signs and signifiers into the virtual world as a kind of short hand. Does this detract from immersion of the game world, breaking the illusion of a new reality? Or does encountering the familiar in fiction allow us to relate faster to constructed environment?