Jonah actually didn't want Ninevah to be saved. He wanted God to punish them for their sins instead of showing the same compassion He had showed Jonah.
I'm struggling with this lesson because we're supposed to want everyone to repent and be saved. Running from our mandate to spread the good news and wishing automatic destruction on the "truly evil" is at least as evil, if not more so, than the ones we are condemning.
Reflecting on Jesus' parable of the prodigal son I was the son who stayed home and resented my brother every time he failed at something and came back home. I didn't think my parents should be constantly rescuing and taking him back in.
Twelve years after his death I'm realizing that I am supposed to offer people the same chances and forgiveness that God has given me. I'm working on being a better Christian and a better person, difficult as it may be.