The Gospel of Mark 1:16-20

In Mark 1:16-20, we read of one of times Jesus called Simon, Andrew, James, and John to follow Him. It wasn't the first time, and it wouldn't be the last time Jesus called these fishermen. In fact, we considered at least four different times Jesus called these men to be His disciples. But why would Jesus have to say, "Follow Me," to them so many times? Why would they hesitate? It's a question we asked and considered our own hesitations in following Jesus. And yet, despite their hesitations and our own, Jesus continues to call.