Jonah was flagrantly disobedient. After God commanded him, "Arise, go to Nineveh..." (1:2) Jonah "arose to flee to Tarshish..." (1:3) Jonah went the opposite direction. God wanted him to go to the east, but Jonah went west to Joppa. God wanted him to go to a city on land, but Jonah took off in a ship on the sea.
Jonah was also flagrantly angry on a few occasions. After God showed mercy to the sinners at Nineveh, Jonah was displeased "exceedingly, and he became angry." (4:1) Later in the book, he said to God, "It is right for me to be angry, even to death!" (4:9) He was angry and he let God know. On two occasions, Jonah said, "it is better for me to die than to live." (4:3, 4:8)
Why was Jonah so disobedient and so angry? Because his will went against God's.
I think I can take this as a warning to be careful when I become very openly disobedient or angry towards God. When I do, I can take comfort in the mighty and patient response of God as he worked to turn Jonah's heart toward His own. He cast Jonah into the deep (2:3), only to bring up his life from the pit (2:6). He made the plant/gourd come up in a night and perish in a night (4:5-11) to teach Jonah eternal truths.
In fact, all that God does in this book is for the good of the people involved: the men on the ship feared the LORD (1:16), the people of Nineveh were not destroyed (3:10), and Jonah was taught. God works in mysterious ways! He is "a gracious and merciful God, slow to anger and abundant in lovingkindness, One who relents from doing harm." (4:2)