This may prove helpful – especially for those who finished the book a while ago: Cloud Cuckoo Land: Recap & Chapter-by-Chapter Summary - The Bibliofile
The same site also has a different set of discussion questions. Again, feel free to ignore, but sometimes they act as a reminder for some part of the book you want to talk about:
Discussion Questions - Set #2
What are your initial thoughts on Konstance and her situation? Does your impression of her change throughout the book?
How would you describe the personality of Zeno as a boy? How does his sexuality affect him, and why do you think Zeno enlists in the military?
How would you describe Zeno’s personality and why do you think Zeno is unable to go with Rex’s escape plan?
What are your initial thoughts on Seymour when we meet him in the book? How does your perception of him change as you learn about him as a child? How does his upbringing affect how things turn out for him?
What did you think of the story of Aethon in Diogenes’s Cloud Cuckoo Land? Are there other stories it reminds you of? What about the story appeals to you or doesn’t appeal to you? Do you think this story would provide comfort to a dying girl?
What did you think of the way the Doerr incorporates the Cloud Cuckoo Land story into the book? How did this add or detract from the narrative for you?
In what ways can the characters (like Anna, Omeir, Zeno, etc.) relate to Aethon’s story? How are their own journeys mirrored by the one told in Cloud Cuckoo Land?
What did you think of the way Doerr structures his narrative? Did you like the way the story it told and the pacing of it?
What do you think of the journey that the Cloud Cuckoo Land book takes (from being found in the priory all the way into the future)? Why do you think Doerr has chosen to tell this story and did you find it meaningful?
What did you think of Seymour by the end of the book?
Why do you think Zeno makes the decision he makes at the end regarding the bomb?
Which character in the book did you like the most? Which storyline appealed to you the most and why? Which storyline appealed to you the least?
What were your favorite and least favorite aspects of this story?
Parts of Cloud Cuckoo Land were heavily degraded, such as the last folio. Were there parts where you had ideas for what could have happened in those missing sections? What do you think about the conclusion that Zeno reaches about how the story ends?
What did you think of the ending of the book? Would you have changed anything? What questions did you have left over?