Eruvin. It is difficult. However, widespread computer concepts help me understand Eruvin concepts. There are virtual “dwellers” and virtual “private domains”.
I see that the famous mosherose is doing Yuma. He will learn that normally husbands are supposed to be with their wives. Only because of the stringent “tahara” concerns with the high priest was he separated from his wife for the 7 days before Yom Kippur.