What you read in English translation is half what was originally there, at least. Each language, although it shares many human tendencies with other languages, has its own approach, its own style, its own emphasis. If you don't understand how that language operates, how it uses language to express opinions and emotions, you will automatically see it from the wrong perspective. You won't understand quite what the author wants to express, and you will miss out on the devices he employs. Some languages use grammatical formations and certain tenses to show a very specific point of reference or attitude which English does not really have.
Some languages use verbs to convey the action, while some use nouns.
That's a brief explanation, but it serves the purpose of this 'Box well. Sure, English is the standard, and it will likely remain the standard, and perhaps become the predominant language for everyone, what with the Internet requiring one language for the true dissemination of information and whatnot, and with international love relationships and higher literacy. But one of the keys to understanding people is through their language. If you learn their language, and you become fluent in it, you become in tune with the ways they use time, the way they tell you how they're feeling, how they think. In this way, you also learn more about your OWN language.