But that's just "learning", doesn't matter if what you learn is totally wrong or totally right. Some things we learn are right when we learn them, but wrong at a later point. And then it's more learning once you learn that it's right or wrong, or maybe it's a bit wrong in that case, but mostly wrong in another, or it oscillates between wrong/right depending on year, location or even mood. There are no universal truths anyways, might as well just roll with it :)
It does matter, because it can affect your whole life. If tomorrow I learn that apples cause cancer and eating plastic is good for my stomach I’ll change my habits and quickly have some issues ;)
But just because someone told you that, doesn't mean you need to operate by that? You can still have your own understanding, follow your own way :) The context here was that it's somehow "dangerous" as in information can "pollute" your brain, just because you read it.