Now this might sound really minimal...because it is, but it has bothered me every time I've ever read the first book.
Why on page 166 did Ron say, and I'm paraphrasing here "that the stone will be gone by Tueday since the stone is only safe as long as Quirrell stands up to Snape".
I REALLY DON'T GET IT!!!! I don't have any psychological problems, promise!!