It takes more than having two hands to be a good pianist.It takes more than knowing two languages to be a good translator or interpreter.
Here is a taste of an interesting article about interpreters, published on PsychologyToday by François Grosjean on his blog Life as a Bilingual, where you can find many interesting posts on the subject.
"Have you ever sat down in an interpreter's booth, put on the headphones and tried to interpret the incoming speech? I did when I was a young and rather naive student who thought that being bilingual meant one could interpret simultaneously. No sooner had I started that problems arrived. As I was outputting the first sentence, the second one was already coming in but I hadn't paid enough attention to it. I remembered its beginning but not its ending. Very quickly I fell behind and I just couldn't say anything more after a few minutes!
Many years later I still remember the scene vividly and because of it, but also because of my own research on the perception and production of speech, I have the utmost respect for interpreters and the training they have to go through to do their job well." (...) (continue reading)
References
Valdés, Guadalupe (2003). Expanding Definitions of Giftedness: The Case of Young Interpreters from Immigrant Communities. Mahwah, N.J.: Lawrence Erlbaum. Grosjean, François. Special bilinguals. Chapter 13 of Grosjean, François (2010). Bilingual: Life and Reality. Cambridge, MA: Harvard University Press.