If I am persuading someone to follow me, I had better have an awesome "hook and bait". Whatever I am offering - whether it be goods, services, a job, or just me (friendship) - it had better be convincing. It helps if you, your goods, services or job that is offered is authentic and of good repute too.
"As Jesus was walking beside the Sea of Galilee, he saw two brothers, Simon called Peter and his brother Andrew. They were casting a net into the lake, for they were fishermen. “Come, follow me,” Jesus said, “and I will send you out to fish for people.” At once they left their nets and followed him.
Going on from there, he saw two other brothers, James son of Zebedee and his brother John. They were in a boat with their father Zebedee, preparing their nets. Jesus called them, and immediately they left the boat and their father and followed him." (Matthew 4:18-22)
Maybe it was the persona of Jesus. Maybe it was the reputation of Jesus. Maybe it was the intrigue to the "hook and bait" statement (pun intended) He made. However, two sets of brothers Peter and Andrew, James and John immediately responded yes to Jesus' invitation.
I think all of it - Christ's persona, reputation, and clever invitation would have caught me too - hook, line, and sinker. It's a wonder what made these men leave their livelihood immediately, but considering the above I would have been sunk at "Hello" (nod to Jerry Maguire - "You had me at hello.").
Notice that the brothers would be receiving a different skill set, but it still would be within the same frame of mind - fishing. God took something the men were very familiar with all their lives, had worked with all their days and asked them to apply it to something of eternal worth - fishing for people's souls.
This change was not a total disturbance of their comfort zone. The disciples dealt with people everyday, they would continue this. The disciples bartered a fair price for their fish every day, they would eventually be instructed and empowered to barter for a change of lifestyle; they would continue showing Christ's compassion to the world and multiply His believers through faith in Christ. The disciples cast a net to catch many fish, the rest of their life would be a learning-journey on how to people-fish.
So, again, it wasn't that God took the disciples out of their comfort zone, it was that He advanced their comfort zone for a higher application. What is it in our life that God has called to a higher application, an eternal worth? Whatever it is, respond "yes" immediately to Him and You Might Be Fishing Soon.