Jesus was very good at telling stories. We are rather less good at understanding them. Some of the stories Jesus told were very clever and multi-layered. We are especially bad at understanding those. Two quick examples:
The Parable of the Prodigal Son in Luke 15 has for a long time largely been understood as being about the "prodigal son". For such a long time, in fact, that the word prodigal has had time to change its meaning rather significantly, therefore making the title doubly inaccurate. It was pretty clear to people who looked at the context and the parable a bit that the elder brother was a more important character than he was often given credit for - he's the one whom the listeners were meant to be identifying with, and so on. But Tim Keller's excellent book The Prodigal God points out what should have been obvious all along - that the central character is the forgiving Father, but that the parable is challenging and illuminating on a whole series of levels - notably by looking at the three main characters in turn.
However, the popular understanding of the Parable of the Sower seems to be heading the other way. Far too many times in the last few weeks, and often by people who should have known better, I've heard it described as the Parable of the Soils. And of course, that is one valid level of interpretation. There is an important point there about how different types of soil respond to the message - which one are we going to be? That may well even be the primary meaning in Luke 8 - the same parable sometimes is used to make different points in different gospels (e.g. the parable of the lost sheep). But the parable is used three times, and it's usually preached from either Matthew 13 or Mark 4, and neither of those passages let us leave the interpretation there.
Matthew 13 doesn't even allow us to call it "The Parable of the Soils", because it is one of the very few parables that Jesus names for us. And he calls it "The Parable of the Sower" (Matt 13:18). And once we realise that it is primarily about the sower, not the soils, it makes more sense.
It's always a good idea to look for surprises (relative to the culture they were originally spoken in) in the parables. So in the badly-named parable of the Prodigal Son, the big surprise is that the Father was watching for his son to come home, and ran to greet him and welcome him back. The parable of the sower (in Matthew and Mark) has two big surprises. One is that the sower sows everywhere, not seeming to care what sort of soil the seed lands on. That is a silly way of sowing. The other is the result - getting a crop of "thirty, sixty or even a hundred times what was sown" (Mark 4:20) is a ridiculously high yield, especially for such a silly method of sowing.
In both Matthew and Mark, these make perfect sense when read in context, because in both gospels the parable follows straight on from people rejecting Jesus, and specifically from the incident where Jesus' mother and brothers try to get him back, but Jesus says that whoever follows him is his brother and sister and mother.
The natural question to ask in that situation and in that culture is this. "If Jesus is someone really special, why are so many people rejecting him?" That's why, too, in both Matt 13 and Mark 4, Jesus quotes a chunk of Isaiah 6 about God's people rejecting God's message. The focus then turns back to the character of the sower in the passage. Why is the sower sowing in such a way? Why is Jesus ministering to people, many of whom reject him. Why isn't he cherry picking the people who are most receptive?
And the parable's answer is that God's strategy is this mad sowing - the telling everyone sowing, and that that method of sowing produces the really abundant harvests. So we shouldn't get worried by people rejecting the message. Something like that, anyway...