The CCC explicitly declares who its audience is, and perhaps it will seem a bit surprising: “This work is intended primarily for those responsible for catechesis: first of all the bishops, as teachers of the faith and pastors of the Church” (CCC §12). The point here is that if the CCC is targeted first of all to members of the Church’s hierarchy, we laymen shouldn’t be surprised if there are things in it that are difficult for us. This is only natural, considering that it’s not written primarily for us; it’s written for men who are experienced with theology.
A natural question might be: “Well then, why didn’t the Church write it for us?” And the answer to that is that catechisms for you and me are left for others to write, using the CCC as a basis:
It is intended to serve “as a point of reference for the catechisms or compendia that are composed in the various countries” [ibid., §11].
Though this isn’t stated expressly here, it seems reasonable to suppose that because the needs and cultures of Catholics worldwide differ so much, it is best that catechisms for use by us laymen be produced by teachers who — because they aren’t writing for a worldwide audience — are able to better take into account local or regional differences so as to create tools for catechesis that are more relevant to us. For example, the needs of a relatively well educated middle class American Catholic will differ significantly from those of a Latin American subsistence farmer. Whereas I might be able to make some use of the CCC for my own self-education, a person who lacks any formal education (and in particular one who lacks any formal theological education) might not be able to do so.
Such a concern for local catechesis also motivated the formulation of the Catechism of the Council of Trent: it was written primarily for pastors, with the intention that they use it as a guide for the instruction of their flocks. So we see that the same concern for local adaptation exists now as in the sixteenth century.
[Update, 2012–07–08: As it turns out I should have read a bit further before posting this, because the point of the foregoing two paragraphs is explicitly spelled out in CCC §24, including even the reference to the Roman Catechism!]
Does this mean that we shouldn’t read the CCC? Of course not. Its secondary audiences include all the faithful and even non-Christians (CCC §12; Fidei Depositum IV). But it does mean, as I said, that it shouldn’t surprise us if we find some things in it hard to understand, and it also means that if we have questions about its meaning we ought to ask questions. We can ask our pastors; we can also ask those for whom it’s primarily intended: our bishops!