Sure you do: the problem is that you dont have the feeling of the currency: only when you pull your calculator and start typing numbers, you have an idea how high or low prices are. I am talking about a walk in the supermarkez, or a shopping mall, where you see lots of prices. Doing that en-masse and continuosly is not feasible for an individual.

Until your google glasses are translating prices in real time, give me my euro.