Eiruvin 66a, b

I found today's daf quite confounding.  Every time that I reread a sentence, it seemed to lead back in a circle and I was not able to place the subject in context.  Unfortunately, I was not able to take more time today to find resources that might help me understand.  And so what I glean from daf 66 is that Rabbi Yochanan and Shmuel hold different positions regarding renting a courtyard from a gentile in certain circumstances.  The halacha is with Rabbi Yochanan.  But even the notes explaining that ruling is difficult for me to follow.  

Some of the ideas discussed in today's daf: inner and outer courtyards, renting on Shabbat, shared properties, ruins between homes -- are by in large alien concepts to me.  I wonder about the idea of living in a courtyard - whether inner or outer - and why construction seemed to be based upon these structures.  It was mentioned in an earlier daf that wild animals were held back by fences, and perhaps this was the reason for courtyards.  How would the existence of courtyards physically shape the structure of society?  Who would socialize with whom, depending on the inclusion or exclusion of people from a courtyard?  How would it come to be that gentiles and Jews might share a courtyard?  These questions are far more intriguing to me than the questions regarding proper placement of eiruvin.  

My hope is that tomorrow's daf offers me a larger window; something with holds for me to grasp on to so that I don't simply slide down the glass, unable to grasp much of anything.