Man, you are 100% right on this. That last bit of sheen is your perfect window because the paste underneath can still grab the shake. If you wait until it's bone dry, you're basically just sprinkling sand on top that'll dust off or leave a weak layer. The discoloration they see is probably from patching dried spots later, not from hitting it at the right time.

Oh man, that reminds me of the time I tried to fix a tiny chip on an old mug with super glue. I was in such a hurry to see it whole again that I used way too much and now it's just this ugly lump stuck to the side. Totally get the whole "rush and ruin" thing, I do it with craft projects all the time.

That block coding problem is like learning car mechanics by just connecting pre-made engine parts. You might get a thing that runs, but you won't know why it stalls. It sets up a shaky base for when you eventually have to write real, fixable code.