Then He said to them, "Follow Me, and I will make you fishers of men."
They immediately left their nets and followed Him.
Going on from there, He saw two brothers, James the son of Zebedee, and John his brother, in the boat with Zebedee their father, mending their nets. He called them,
and immediately they left the boat and their father, and followed Him."
Matthew 4:18-22 (NKJV)
Any type of journey means traveling from one place to another. If you never move from where you are you will never get to where you want to go. Also, when traveling to some other place you have to have some directions and then follow those directions to reach your destination. Sometimes, depending on the journey, you not only have to leave your current location but you may have to leave some other things behind as well, and if you don't you won't be able to take the trip. For example, to travel by airplane there are restrictions to the amount of luggage you can bring with you.
We don't really know every story of how all the disciples met Jesus, but in Matthew 4 we can see how Jesus called Peter, Andrew, James, and John to follow Him and we can learn some important lessons. For example, these disciples were not some unemployed, homeless people who had no purpose in life. These four disciples were part of a business, and in the case of James and John it was a family business. But, when Jesus called them to follow Him they left everything to do so, everything! Think what they would have missed if they had stayed where they were with what they had.
The point is not that Jesus wants us to forsake our possessions or our family. But, to truly follow Jesus and go where the Holy Spirit will lead us, there are some things we may have to leave behind. If we try to hang on to what we have and where we are we may have a hard time following God's direction. Does God want us to have a great life and nice things? Yes! Does God have a wonderful success filled plan for our life? Yes! But, if we put our goals, our possessions, and our plans ahead of God's we can have problems. We need to be like the disciples who were ready to leave everything behind to follow Jesus, that leads to true success and satisfaction.