Keep worrying about it, the nervousness is good for keeping you from sleeping too heavily. ;-) I like to wake up once or twice in the middle of the night and check on things when at anchor. At the very least pop my head out of the hatch and make sure the last visual marker I recall is still in roughly the same spot.
Every time I ask my wife if she wants to sleep on the hook, her immediate response is, "NO, you never sleep when we are anchored."
I have since found a small bay on our protected lake, about 8 - 10 feet of mud bottom. Now, when we anchor there, I sleep like a baby.
Courtney is My Hero
If a man is to be obsessed by something, I suppose a boat is as good as anything, perhaps a bit better than most - E.B. White