I quite agree. You can't advance if you don't confront challenges. That doesn't mean you have to hurl yourself headlong into unknown territory.

My favorite author, Christopher Moore, wrote a book called Lamb some years back, which is an amusing satire of religion. When I was taking German at University, I purchased a German language copy of the book so I could practice comprehension. I'd read Lamb a half a dozen times so I reasoned it would aid comprehension, as opposed to buying a book for which I had no exposure.

I would recommend a similar strategy for parents who wish to get their kids started early on second language acquisition. Look at what books they like to read and buy the same in other languages. The sooner kids start in this regard, the better will be their chances of being bi- or even multi-lingual as adults.