One of the first joys of a young priest is being able to say those four short words at the beginning of Mass — instead of answering them as a server.
The server answers with the words,
Ad Deum qui lætificat juventútem meam.
Priest and server start off the Mass in joy. I will go in to the Altar of God. To God who giveth joy to my youth.
My prayer as I begin my ministry is that every day will start with those thoughts: a joy in the service of our blessed Lord in His Church.