Love for Jesus is not necessarily spontaneous, but it can be. We just need to look at some of Peter’s responses to Jesus which were enthusiastic, but then he denied Jesus. What happened to Peter’s love for Jesus? It needed to grow.
Looking at what happened later for Peter, his love must have grown for Jesus somehow. He showed his love because he went to places that at one time where uncomfortable for him to go to, but which Jesus told him to go, which meant he had grown in love for Jesus.
Peter’s lesson in love is that love grows. So in our lives, our love for Jesus can grow step by step and not always in one go. One day we may feel able and equipped to go to places that once we feared going because we have grown in love for Jesus and Jesus told us to go there. We love Jesus now, we may love him even more later on.
Growth in love for Jesus can come through getting to know him through prayer, praying and meditating on the gospels, and growing in our spiritual lives.