A "gracious" perspective on the parable of the ungrateful servant

From Phillip Yancy:

"It was altogether in character, then, for the scrupulous apostle Peter to pursue some mathematical formula of grace. 'How many times shall I forgive my brother when he sins against me?' he asked Jesus. 'Up to seven times?' Peter was erring on the side of magnanimity, for the rabbis in his day had suggested three as the maximum number of times one might be expected to forgive.
'Not seven times, but seventy-seven times," replied Jesus in a flash. Some manuscripts have 'seventy times seven,' but it hardly matters whether Jesus said 77 or 490: forgiveness, he implied is not the kind of thing you count on an abacus.
Peter's question prompted another of Jesus' trenchant stories, about a servant who has somehow piled up a debt of several million dollars. The fact that realistically no servant could accumulate a debt so huge underscores Jesus' point: confiscating the man's family, children, and all his property would no make a dent in repaying the debt. It is unforgivable. Nevertheless the king, touched with pity, abruptly cancels the debt and lets the servant off scot-free.
Suddenly, the plot twists. The servant who has just been forgiven seizes a colleague who owes him a few dollars and begins to choke him. "Pay back what you owe me!" he demands, and throws the man into jail. In a word, the greedy servant is an ingrate.
Why Jesus draws the parable with such exaggerated strokes comes clear when he reveals that the king represents God. This above all should determine our attitude towards others: a humble awareness that God has already forgiven us a debt so mountainous that beside it any person's wrongs against us shrink to the size of anthills. How can we not forgive each other in light of all God has forgiven us?" -What's So Amazing About Grace?

I saw this coming as I read it. This is painful to read. As much as I have a hard time receiving it, I love Jesus' forgiveness. Yet, I am less excited about giving it. What lack of understanding I must have to joyfully stand at church on Sunday receiving God's unmerited grace and forgiveness for an unrepayable debt, but to struggle so much with giving forgiveness for a very forgivable debt that doesn't even belong to me. ("Against you, and you alone, have I sinned God...")