Repent: To think differently or afterwards, that is, reconsider (morally to feel compunction)
Compunction: A pricking of heart; poignant grief or remorse proceeding from a consciousness of guilt; the pain of sorrow or regret for having offended God, and incurred his wrath; the sting of conscience proceeding from a conviction of having violated a moral duty.
Repent holds both the pain of disobeying the all loving and all powerful Just God of all, and then turning away from what caused that pain.
I can think of two examples of this, first we have a good buddy of mine. Josh was a meth addict who loved the needle and cooking, God brought Josh to his knees and showed him the err of his ways. Josh felt such an immense pain and regret for the way he had lived his life that he took that second part of repentance. He turned away from meth and turned to the tender mercies of God, thus through the power of Christ's sacrifice Josh became a new man (literally, true salvation carries with it the new birth). Second would be a person already walking with God, he disobeys the law of God and immediately feels the conviction from the Holy Spirit. Filled with the first fruits of repentance (the pain of dishonoring God), he turns from that sin yearning for strength and guidance from a graceful and loving Father.