Let me put it this way.
The Church before the Vatican II could, and largely was perceived as castled in a staunch repudiation of the modern world. Still today, as a matter of fact, its moral teaching is perceived as a series of no: interdiction of this, interdiction of that… especially with regard to sex (as if she were concerned about sex as such, and not about people to whom is given to be, among other things, also male and female).
The inspiration of Vatican II, eminently in Gaudium and spes, was to come out of such a castle, stop condemning the modern world, and come toward it in understanding.
The right and just thing to do. But it could be equivocated, as unfortunately it has been, as advocating an adjourning of the Church, and us in her, to keep up with the modern world in all its changes.
Benedict now is telling us, in all his teaching and preaching that goes under the label of hermeneutics of continuity, that the modern world doesn't exist, so to speak.
I mean, all the changes of which Gaudium and spes talked about, and more, are real. But, please, let's not conceptualize them as we are used to do, as "modern". It is the negation of thinking, which requires a capability of taking distance from ourselves, rather than putting ourselves, in our fleeting now between past and future, at the center. Torn, as the case might be, between nostalgia for the vanishing past, and expectation for whatever change the future is bringing.
"Modernity" is a false category, that leaves us without capability of drawing from the past criteria of judgment for the future, what it should and what it shouldn't bring about, and to act accordingly: to achieve the first and to avoid the latter.
Right is Gaudium and spes there, where it reminds us that at the center is only Christ, in his eucharistic being always, now, between was and will be.