Here is an excellent short summary.Hmm... okay... that's not what I read, and it worked in a negotiation with some Chicago lawyers, but I guess I need to dig a bit deeper, which I will now do since you made your statement, but, if you've got a link that cuts to the chase, that would be nice.
What's so weird about it?
In any case, and since we're on the topic... what are your feelings about judges being obligated to "precedents"?
The Common Law and Civil Law Traditions
As to precedent, it is a common-law concept. The key to precedent is that a court must follow the prior decisions of itself or a superior court in the same system. That last is key.
In the United States, for example, all Federal courts must follow Supreme Court precedent, but a district court in California need follow only Ninth Circuit precedent, the decisions of the First Circuit (New England) are not binding upon it.
It's generally the same with state courts, but there are always exceptions.