I'll believe you've seen people saying that kids learn languages faster, but I'm not :) There's a lot of research both ways, and second-language acquisition is very similar to first-, but there's definitely something different going on or we wouldn't have any idea how a baby can learn a language starting from knowing none.

There's also solid evidence that learning two or more languages as a child, while being slightly slower, sets you up better to learn more as an adult, as well as just making you a cooler person overall.

That aside, though, I share your skepticism. I was just relating my experience, and hoping maybe we could, you know, have a conversation about it :)