Not trying to brag, but due to my background I ended up trilingual (Korean, Spanish and English).
It all depends on circumstance - I spent a few years growing up in Korea, Latin America and the U.S - and went to school in all three countries where I was forced to learn the native language. It's been a few years but I still speak all those languages due to friends and family so I haven't lost the ability yet.
It's not a very useful skill for my job - but I just wanted to point out that I can attest that immersion as a child is one of the best ways to learn languages.
It all depends on circumstance - I spent a few years growing up in Korea, Latin America and the U.S - and went to school in all three countries where I was forced to learn the native language. It's been a few years but I still speak all those languages due to friends and family so I haven't lost the ability yet.
It's not a very useful skill for my job - but I just wanted to point out that I can attest that immersion as a child is one of the best ways to learn languages.