It's not quite the case.
In "Familiaris Consortio," John Paul II said that we need to have remote, proximate and immediate marriage preparation. Proper marriage preparation cannot be squeezed into six brief months. Rather, it begins at birth. The same would be true of a vocation to priesthood and the religious life. If this is the case, then rather than approach the topic of preparation for one vocation or another on two different planes, perhaps we should approach them like a "Y." The same formation continues through childhood and adolescence and eventually branches into one particular preparation or another.
If our specific vocation springs from our universal vocation to love -- which we receive upon our first moment of existence -- then our specific vocation preparation should begin from Day 1 as well. This preparation is always a training in love. It is further specified as we discern, realize and receive the way in which God calls us to love.
How can we begin from Day 1?
• Awareness of being a child of God
• Desires as a prayer (hungry, tired, etc.)
• Receiving, not grasping
• Love = willing the good of the other
• Modesty = body is good, so we treat it as a treasure
• Priests/religious as a sign of heaven
• Marriage as a sign of God’s love
• Praying for priests/consecrated/married people
• Sexuality as a precious gift
• Language of the body
• Beauty = reflection of God’s love
• Prayer as communication with God in which God shares His life with us and leads us on a path to Him in heaven.
• Crucifix as a reminder of real love
• Suffering – “offer it up” as fertilizer for seeds planted by God.
If we want to pray for vocations -- which is a very good thing to do! -- we musn't sit back and wait for the Fairy Vocations Godmother to wave a magic wand and turn random people into faith-loving, Gospel-sharing, God's love-reflecting priests, religious and married couples. Rather, the pray for vocations must accompany a commitment to assisting others in receiving their call from God from the first moment of life.