The parable of the sower always seemed like a competition when I was growing up. Another story to find out who is right and wrong because if you receive the word then you yield fruit. It's important to note that the disciples did not understand this parable they had to have Jesus explain it to them. A part that was always overlooked when I was a child. If the disciples didn't understand this and had to have it explained does that mean they were really one of the seeds thrown on another soil?
Growth happens, sometimes not in the way we want or the time frame we picture. We have our own path to follow and you can't really name the soil or how the plant is turning out by just glancing at it. Growth happens through struggle, the disciples had much to struggle with once Jesus was crucified and all their dreams died and were resurrected in another way. Growth came to them.
This is the way it may come to us, not in apparent measurable terms, but through struggle. When we struggle with things we grow in new ways that we don't expect. It usually means we have a change of perspective on our life, on God, on who we are and what is expected of us. This is kingdom work and it's not easy. We can't make it happen we have to follow the path, notice our growth, and surrender to something that is greater than ourselves. Being attentive is the hardest kingdom work we will do.