This seems like a good time to insert the lecture again.
Being familiar with a hill means you know where the line goes - camber, turn radii, cracks and potholes, etc.
It does NOT tell you whether there is an obstacle or a slippery surface around the next blind curve, or whether a deer or groundhog is about to dart across the road.
If you notice yourself getting a
lot faster as you become familiar with a hill, search your soul as to whether you could really stop or swerve in time if there was oil or gravel just around the turn, or whether (in the classic
Motorcyclist example) one lane was blocked by a refrigerator, and the other by the pick-up truck that just dropped it.
The limit on your speed should always be your sight distance and your braking and swerving skills. Work on those skills and enjoy those descents! (I love them!

but I know I can be a little over-bold and ought to be doing more skills drills.

)