Learning a language from an early age is far easier than when you are older. Kids have all the time in the world, which adults most certainly don't. Beginning early builds a solid language base, which can be widened and cemented as you grow up. It may also help you with future job prospects, for example, in the management sector where language is of utmost importance. In my opinion, to truly master a language, you must speak and practice it over a long period of time. I personally grew up trilingual. This has helped me speak the 3 languages I learned flawlessly.