This is often called the Parable of the Sower and the Seed. Maybe we should call is the "parable of the dirt." The seed is always the same. The dirt is different. Different dirt receive the seed in different ways and the results are therefore different.
People are different and receive God's Word in different ways. So the results are not the same. Jesus tells us to plant the seed and leave the growth up to Him. Our job is to plant the seed, to tell people about Jesus. Have you done any planting recently?