Reading how Jesus called his disciples, I am always perplexed at how they just leave everything and start following him. An example passage:
Matthew 4:18-22 (ESV)
18 While walking by the Sea of Galilee, he saw two brothers, Simon (who is called Peter) and Andrew his brother, casting a net into the sea, for they were fishermen. 19And he said to them, "Follow me, and I will make you fishers of men." 20Immediately they left their nets and followed him. 21And going on from there he saw two other brothers, James the son of Zebedee and John his brother, in the boat with Zebedee their father, mending their nets, and he called them. 22Immediately they left the boat and their father and followed him.
It's really amazing that anyone in their right minds would act like that. Now, one might think that Jesus does some miracles that just aren't mentioned. However, his first sign was at Cana and he already had disciples at that time.
John 2:11 (ESV)
11This, the first of his signs, Jesus did at Cana in Galilee, and manifested his glory. And his disciples believed in him.
Why were the disciples so eager to start following Jesus?