- whether mourners sit or stand in comparison with those going through chalitza
- overturning the bed
- learning - is the mourner going to be comforted by learning? or distracted?
- wearing tefilin on the first, second, third days of mourning
- greeting people/being greeted at days 1-2, days 3-7, up to day 30, up to 12 months mourning
- when and how we speak words of consolation to mourners once past the 30-day mourning period
So the Gemara is quite clear - generally we are not learning about mourning rituals that were in place at the time of writing. And when we are looking at established rituals, the rabbis are often unclear as to why we do those things. Over and over, the rabbis tell us what different Sages did in different communities. Based on these actions, the rabbis decide what should be formally ritualized.
The rabbis discuss rituals that might have taken place in the past. They share stories regarding different practices. The rabbi with the most clout tends to create the halacha which has been taught, then, from generation to generation for literally thousands of years.
Again it is jarring to confront the origins of our current ritual practices. Sometimes very established, seemingly meaningful rituals are actually based upon "maybes"; interpretations made thousands of years ago. What if those interpretations were simply opinions of those with social stature, education, and power? What if those very important mourning rituals are based on sources that I cannot grasp - or with which I disagree?
Ultimately, and I come to this over and over, Jewish rituals continue to provide me with comfort, community, and questions. The fact that generations have said these same prayers before me, bowed at the same time, sat in lower chairs when in mourning and not worn tefilin at certain times when mourning - all of these rituals are imbued with the meaning that has been instilled in each of them over those generations. I don't need to understand and I don't need to agree - I just need the rituals.
But i do need to learn - to know the sources behind the traditions. Hence daf yomi.