This morning at NLM Peter Kwasniewski makes some points about liturgy and memory, memorization, which are quite good… so good that I have made them myself in the past. Here is a good bit:
This requirement [for priests who say the Extraordinary Form, Usus Antiquior] of memorization, far from being a mere guarantee of efficiency, has its own profound value: it is one more way in which the ancient liturgy demands that the celebrant “put on the mind of Christ” — or better, enter His Heart — by means of “knowing by heart” certain prayers of the Church that mold him into the image of their sentiments.
Prayers run the risk of remaining external to the celebrant as long as they are merely written in the Missal, because their location is an external book. Memorized prayers, on the other hand, are already internal(ized) and, as such, are more available as a wellspring of piety within. The heart has become the book, the living book from which the Mass is celebrated.
The same must be said for catechism and children (or adult converts). I have related in the past how at a hospital I was confronted by a woman whose father was dying. She was very angry at God and everyone else. “Why would a God make us just to wind up like this!”, was the essence of her anger and sorrow. I asked her, “Why did God make you?” She calmed down and gave the precise Baltimore Catechism answer, which then helped her to deal with her father’s death.
Once you have it inside then it is yours.
I have also often opined that priests should memorize at least one set of texts for a Mass, perhaps a Votive of the Blessed Virgin: there might come a day when you, in hiding, have no books, etc.
Have a look at Peter’s thoughts. There is a lot to discuss.