Haha, I usually skip over it. It sucks the most when someone quotes me so I get all excited expecting to read something about some interesting thing I said but instead it's a HP joke.
Yellow does mean stop. It means "stop unless unsafe to do so". I just got my license and did drivers training, so I know that's absolutely what it means.
Also I just turned 18 today. Within a week it's crazy how much more freedom I have.
Edit: Oh wait, do you mean flashing yellow at like night time?
You're Canadian, you know how to drive...and merge.
And Happy Birthday, from your friendly neighborhood Potter