Jesus used parables to get his hearers attention and farmers knew very well when  he preached a message about the four soils and the seed, but they didn't get the spiritual applications---only his disciples had. Sowing and reaping is an old testament law that started back in the days of Adam. In fact, the LORD God (Adonai Elohim)'s government of sowing and reaping. Every seed bears something: fruit-bearing seeds yields fruit, herb bearing seed yields herbs. God is very much into people bearing fruit and the seed people use is called the word of God.
He who hears let him hear.
Jesus told his disciples that they are permitted to know the secrets of the mystery of the kingdom of God. He continues to tell them what the seed is and no surprise to that, it is HIMSELF!. If you look it up in accordance, the reference number is 4703. Go down the list and the same reference number is used for Jon 1:1 "In the beginning was the WORD, and WORD was in the beginning and the WORD was God. Some people have problems with Jesus being God. They can't see God on the cross, but God is plural (Elohim). In many denominations, people believe in the trinity: God the Father, God the Son and God the Holy Spirit. Jesus is the word of God.
The above scriptures in natural would be an impossibility, but you have to look at in another context. We have to assume that the blessed person sows seeds just as the farmer sows seeds in the parable. And what exactly is all waters? Does it mean you have to sail in the boat to do that? No. Often times in the scripture, there is symbolism, and waters represents people and nations. The blessed person is one who tells everyone about Jesus!  "Jesus saves!" "Jesus heals!", etc.
Not everyone receives the good news about Jesus. Some will hear it but before they can let the word take root, the enemy will take it away. Some will hear it but when persecution comes, they will fall away. Some will hear it, but deceitfulness of riches and cares of life will choke the word out of them, but others who will receive it gladly. Those who do will multiply the kingdom. Jesus often will state what the kingdom of God is like and other times will use parables to tell his hearers how the kingdom is operated on. In this one, its the law of sowing and reaping. Sow seed on good ground and you will reap a harvest of souls. 
So go out sow Jesus into people's lives! Sow the word of God and be blessed!

Scriptures in the old testament pointed to Jesus as the Messiah and the Jews knew it. The problem was they had a wrong understanding what the Messiah was. They believed that the Messiah would free them from Roman control and that he would be their early king.
The disciples believed it too.  Yet three times Jesus said how he would die and rise again. At any time he did not say, he would conquer the Romans for them and sit on an earthly throne yet the disciples didn't get it.
James and John had big heads. They imagined reigning with Jesus that they wanted to sit next to him in his glory. All they could think about was themselves! Even in one gospel account, their mother had the same request for these two disciples. They did not get it.
Jesus understood and put them to the test. "Can you  drink from the same cup and partake in the same baptism I will partake from?" Do you think they understood what that meant?
When they answered Jesus that they could, he sadly informed them they will, but he said it was not for him to decide who will sit next to him. And here is where he put them in their place. He told them that those who wants to be leader must be a servant and he closes with, "for the son of man did not come to be served, but to serve."  Jesus didn't deny his kingship to them, but stated that his kind of kingdom is not of this world as oppose to the gentiles who wants to rule over their citizens.