Forgiveness?

A riff off of yesterday’s sermon on Matthew 18:21-35, in the midst of yet again removing safeguards from Americans' healthcare:  

How does one…a slave no less…come to owe ten thousand talents (the guesstimates of such a sum in modern terms range from over a million to multiple millions of dollars)?  

Perhaps by living in a society where the system of power leads to terrible injustice.  I imagine where a king has the sole ability to pass judgement and forgive out of his abundance:  and then hold everyone to his standard of “forgiveness” even though the system remains corrupt. 

Or maybe a society where being born with complications to a family without healthcare leads to unplayable amounts of debt?  Or an endless series of all to imaginable healthcare complications in one's lifetime that leads to drowning in bills?   

Only one person forgives anyone in Jesus’ story:  the king.  He forgives only once, then acts in anger and condemns the person to perpetual torture for failure to “forgive” like the powerful king that he has nothing in common with at all.

What was Jesus really trying to teach his disciples after first saying they must forgive “seventy-seven times” and then telling this story?