According to the ordinary knowledge of the universe current at the time, it could not have occurred to the theologians or Church authority that when Genesis speaks of the six days of creation, and itemises what happened on each day, that this was poetic rather than literal. Today, the increasing knowledge of the universe, along with the rapidly accumulating evidence for the unified and organic evolution of the universe and all things in it, caused many to say that the traditional way doctrine was taught no longer makes sense. The Church while not denying doctrine, reformulated it radically, so that believers could take it seriously. Today people are more comfortable with an account of creation that has incorporated all we currently know of evolution. Thirty or forty years ago many were still worried, and fifty years ago almost all Catholics believed evolution contradicted faith.
Theological development: every believer has a part to play, but not all are properly equipped to do so. When the faithful say that existing explanations do not make sense any more, it is a wake-up call to theologians that it is time to reconsider why these formulations were made in the first place, what was the important message and the historical circumstances leading to such a formulation. Having made this study, theologians then attempt to reformulate doctrine in a way faithful to the Christian message, but which is also up to date for contemporary believers. Not an easy task! They try to do it in different ways, according to what their people share with them. The way theologians think in Italy and Spain will differ from those in Central Europe, for example.
Dogmatic development: because the experience of various kinds of believers is so different, there are often clashes between different schools of theology – sooner or later, because of differences, they will ask the teaching authority of the Church to intervene with an official version. There are usually many ways of expressing the truth; there has never really been only one correct way of doing it. The teaching authority of the Church has no hot line as to which is the better way. Even when infallibility is invoked by the Holy See or a General Council it does not mean that this statement was made on the basis of a new revelation. It means that it claims to be the authentic interpretation of what the faith of the people as a whole has always explicitly been or implied.
Such statements tend to be conservative, because that is their purpose. This does not mean there has been no dogmatic development. It takes third place because there cannot be a judgement on something until it has been discussed [the role of theology], and cannot be discussed until human experience has given rise to the query [the role of all faithful]. Some feel guilty when thinking differently from official pronouncements. They should respectfully and responsibly express this mismatch, because this is how development of doctrine has always taken place, and must continue to do so.