Ecclesiastes – “Shit happens, and then you die.”
Job – “God, how does the sausage get made?”
Song of Songs – “Your breasts are like two fawns. Hehe.”
In all seriousness, though, I think these three books contain the entirety of human wisdom. Ecclesiastes tells us that life is meaningless…it’s all a chasing after the wind. Doesn’t matter if you’re good or bad, wise or foolish, you’ll all end up below ground. Then Job teaches us that even if life has meaning, we’re still on our own, because God won’t tell us. And Song of Songs says if you’re lucky enough to meet someone to share a few fleeting moments of joy with in this crazy life, go for it.