Prophets were not just vain dreamers of people who had extraordinary visions. In fact I don't remember John the Baptist being a dreamer or seeing things but he was indeed a Prophet. He was indeed a person who could discern what he saw in front of him and a person who read the sciptures and prayed. As a rule most prophtes tend to call people to repentance and exhort people to believe and be faithful because God has weighed them and found them wanting. It dones't really take much of a look at the propets of scipture to realise it was probably the worst job God could give anyone as far as this life is concerned. However, when even someone who gives a cup of water to a Prophet, because of his calling, will not lose their reward how much more will the Prophet be rewarded.
Blessings,
Mel