None of these concepts of "following" hase anything to do with what Cardinal Ratzinger was talking about when he chose the words "follow me" in his eulogy for Pope John-Paul II. He was, rather, drawing on the Biblical sense of the term, which deserves some unpacking.
The proper context for understanding this language is twofold. First, we need to understand that the Jews who wrote both the Hebrew Bible and the New Testament were fond of seeing the life of a disciple as a journey which involved conscious earnest efforts to move forward. They would talk about walking in truth or walking in the light, or, as Paul puts it in Galations 5, walking in the Spirit.
The believer's life is not seen as something that just happens to them while they are in a static state, it is rather an endeavor, a pursuit, a journey. It involves intentionality and effort. Christian life is not something you have, it is something you do or pursue. It is always in motion, always progressing or regressing, always going somewhere. In this context we are prepared to catch the pedagogical nuances when Jesus commands his disciples to "follow me."
In the world of Jesus, teachers and sages had students who were called "disciples." The main means of teaching in antiquity, besides simple memorization of a teacher's words, was what we call modeling. Disciples were to imitate the behavior of their teachers. We see this in Mark 6:7-13, where the disciples are sent out by Jesus two-by-two. and they undertake the very same activities they have seen Jesus do--preaching, teaching, healing, casting out demons.
Imitation was of the essence of being a good disciple, and so when a teacher or sage said "follow me," he meant "do what you see me doing, and say what you hear me saying."
But there is more implied in "follow me" than even this. In principle, when Jesus says "follow me," he also means that he is not sending his disciples to do anything or say anything that he was not prepared to do first, and to show them how to go about it.
Following Jesus meant far more than just traveling with him, listening to his teaching, being healed by him and the like. It meant to be prepared to imitate his pattern of life, even to the point of death if necessary. This is why we regularly hear in the Gospels-"if anyone would come after me, let him take up his cross and follow me." Jesus is suggesting that he was leading his disciples on a path that required in advance the willingness to make the ultimate sacrifice-giving up one's life for the cause.
Cardinal Ratzinger aptly cited John 21:21-22 in his eulogy. In that text, Peter had noticed the Beloved Disciple, and was concerned because there was a rumor that he would not have to die before Jesus returned. Jesus says to Peter, "If I want him to remain alive until I return, what is that to you? You must follow me."
Peter was to keep his eye on Jesus, and follow Jesus' example, even including his manner of death. It was not for him to compare his life to that of other disciples, but was instead was to follow the paradigm of Jesus' own life.
We now know that the Pope likewise had a moment like Peter where he asked God the question-"Should I keep going down this path, or should I step aside and let someone else take the lead?" Apparently the Pope wondered if he should act like other Christian leaders, who simply retire rather than serving full-time until the end of their lives. The answer the Holy Father received was the answer the original disciple Peter received.
Pope John Paul apparently was not concerned with having a following, but rather with being a follower of his Master. He was not apparently concerned even with fully "following" or understanding the whys and wherefores of his life pilgrimage. Nor did he consider "following" simply a matter of what's next. It was rather enough to know that he was on the right road, walking in the light, and following wherever Jesus would lead him.
The reward for a life so well spent was neither having fans nor understanding all the meanings of one's life, or undertaking just one more task, but rather hearing his Master say upon his death, "Well done good and faithful servant; inherit the Kingdom."
We may trust he has by now heard the Lord say those very things to him. We may hope that the next Pope is nearly so good and gracious a follower of the one who said "Follow me."