In a sense Jesus has upped the ante miracle-wise for the disciples in walking on the Sea of Galilee in the midst of a storm. Notice that as the Gospel of John progresses, Jesus generally performs greater and more powerful miracles to fewer people, climaxing in His raising of Lazarus from the dead. He is also becoming more intense in His teaching, dividing His listeners between those who will give up everything to serve Him and those more interested in seeing miracles and going along for the ride. Jesus performed miracles for various reasons: healing miracles were done from a heart of compassion; but miracles Jesus performed also brought crowds to see Him, demonstrated that He was the Messiah-here the crowd compare Jesus to Moses and Jesus will demonstrate far greater powers than those given to Moses in Egypt and in the wilderness-and He particularly focused on the disciples, those people who He spent nearly all His time with for three years, telling them things He didn't tell His general audience ( Luke 8 v 9-11 ) and preparing them successfully for a life of witness and deaths as martyrs.
Notice again that Jesus doesn't answer the crowds question, verse 25, 26, but, as always, draws them deeper. There was a huge range to Jesus' teaching. There were very straightforward stories full of images known to the Jews and then there was teaching as in this chapter which can only be understood and received by those prepared and open to God already. I would argue that it is not intelligence which enables us to grasp Jesus' teaching in this chapter, but spiritual awareness, and I have known plenty of people who are not amongst the world's finest intellects, yet understand and accept some very profound areas of Christian teaching. Read 1 Corinthians 1 v 18-28 for encouragement!