Will you defrob my balancator? Of course not, because you don't know what it is. The same applies here: if you don't know what something means then say no. If you say yes then it's understood that you know what you signed up to.
But anyway, I think even that is beside the point. I think the point is that there are things Europe considers fundamental rights. And the concept of a "right" doesn't.. really.. make much sense if someone can go "btw we'll just violate it, click to agree."