Just in case you truly want to know the history behind the concept:
http://www.catholicculture.org/culture/liturgicalyear/activities/view.cfm?id=1098
Slyfox,
Thank you for your kindness in posting a link to share the Roman perspective on this concept.
It is interesting reading.
Absolutely noting wrong with spending time meditating on the love and grace of God, as represented in the sacrifice of Christ. I wish more Christians understood what that sacrifice actually means, why we must entrust ourselves to it for salvation and judicially & positionally, what it accomplished. Unfortunately, it rarely, rarely rises beyond thinking about His suffering and love.
Thanks again.