For the love of god, tell kids we don't know
Physics is solved. Or so I thought when I was 13.
There are a few equations you have to know, true, but the only thing left is applying them to any situation we want. I couldn't do it myself (I was 13 after all) so I understood that there are things left to learn, although the required skills were purely computational. State your problem, look up the right equations, solve them. I imagined being a physicist was a cozy but at its core a boring profession.
Obviously, I was lied to. It wasn't that someone said something plainly false, just that everyone didn't say that the world is complicated, we know we don't know a lot, we can't even agree on what we know, even if we have equations we may not be able to solve them in any practical cases - or even agree on what the variables mean!
I thought I loved physics back then but I hadn't had the slightest idea of what physics actually was to really say that. Actual physics is incomparably more beautiful, confusing, challenging, exciting, messy and fun than what I was taught.
For the love of god, don't keep kids in the dark, just say we don't know shit, that there's plenty of exciting discoveries waiting and children will get how exciting this is! I wish somebody told me when I was 13.
(I know they aren't reading but I would like to thank my amazing high school teachers (like two of them) and university lecturers (more than two of them) who by their sheer awesomeness managed to rekindle the spark within me after what middle school did to me)