If I've learnt anything from teaching kids it's the ones really good at it when we start are completely dwarfed by the kids who sucked at it.
You can get kinda far without really understanding what's going on, but if you stop and have to learn something really fundamental the "good" kids just seems to manage. Once things pick up they can excel because the have truly moved on. the previously "good" ones are still copy/pasting from past work or tutorials and get brackets wrong whereas the "slow" ones are now perfectly happy writing from scratch and thinking for themselves.
You can get kinda far without really understanding what's going on, but if you stop and have to learn something really fundamental the "good" kids just seems to manage. Once things pick up they can excel because the have truly moved on. the previously "good" ones are still copy/pasting from past work or tutorials and get brackets wrong whereas the "slow" ones are now perfectly happy writing from scratch and thinking for themselves.