Can the Atonement be simplified?

I was touched by the quote Sarah included from Hugh Nibley. I am forced to wonder if I am someone who truly does NOT understand the atonement in its entireity. It is humbling to think I am someone who has been charged with the task to teach the children in our ward gospel truths--including this topic.

When I recently tried to explain the Atonement to our (junior) Primary children (ages 3-6) (we've got a lot of little kids in our ward), I struggled trying to find an analogy that they might grasp. After much thought it occured to me that Christ's Atonement was his way of serving our "time-outs." Even small children know that when they hit a friend, throw food on the ground, yell at mom, or tease a sibling, their punishment is set and in many homes, involves a punishment like a time-out. No matter how hard my kids beg not to go to time-out when they've done something wrong, there is no negotiation. They did the crime, now they must do the time.

In the case of the Atonement, the "crime" has been done by each of us--the crimes are many and varied, in some case they are sins of omission. No matter the misdeed, however, Christ serves our time-out for us, and we reap the reward--the eventual chance to become a God ourselves! This is the most amazing example of selfless service I can think of. Christ does not withold his "time-out serving" for anyone, no matter how despicable the person or the sin.

The kids "got" this concept, but I would like YOUR help with something. I believe it is in Alma (I'll try to look this up later) that we learn that Christ not only suffered for our sins, but he also took upon himself our sadness, sorrows, infirmities, and sickness. How does this knowledge fit into my little "time-out" analogy?

Also, I'd like any other ideas you have for teaching children about the Atonement.