A nugget tucked away...

I found this verse a few months ago tucked into the gospel of Luke, and I have been pondering it ever since, here it is along with my thoughts. If you can add your own insight to this passage, I'd love to hear it.
Luke 22:31-32 (Jesus is talking) "Simon, Simon, Satan has asked to sift you as wheat. But I have prayed for you, Simon that your faith may not fail. And when you have turned back, strengthen your brothers."
This is one part of the conversation Jesus and Simon (also called Peter) have during the Passover Supper (or the Last Supper). It's where Jesus tells Peter that "before the rooster crows, Peter will deny Jesus 3x.
Here are the things that struck me as I have read this passage and mulled over it.
1) "Simon, Simon" I love the tenderness in Jesus using Simon's name twice. I can just hear His tone (as I think it might have sounded), not harsh, not condemning, but filled with tenderness as He warns His disciple of what is to come.
2) "satan has asked..." For some reason, I get so much comfort from knowing that Satan had to ASK to come against Simon. (Just like he did Job) I wonder what it was about Peter that made him such a target for Satan, I mean, why did he specifically ask for him?
3) "but I have prayed for you" This is JESUS praying for one of His disciples. It amazes me that Jesus intercedes for us. I don't know much about the theology behind this, but in my "theological" mind, I am in awe of Jesus interceding on MY behalf. I think of times that I've gone through struggles and trials, and I look back so differently thinking that Jesus was praying for me.
4)"And when you have turned back"...This is probably my favorite part. Not, "if you make it through", Not, "good luck to you, man"...but "WHEN you have turned back". Jesus is giving Simon a glimpse into the future and a knowledge that he will get through whatever it is that Satan will put him through.
Those are just some of my thoughts on this passage that I have somehow managed to miss in years and years of reading the gospels. This comes to mind so often when I hear of someone struggling with something. I've been trying to find sermons and talks on this verse, but so far haven't found much that gives me further input than my own simple mind.