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I tought i had gotten everything in the first chapter but i just saw a video on youtube that Geralt talks to Dandelion and refers to the flash back he had when talking to Ciaran as well as the manuscript that Morten Collis wrote. I would like to know where do i find this manuscript and know why i am not getting the dialogue option to talk about my vision with Dandelion.
You find the manuscript at the Claws at Madness quest started in the forest or talking to the elf in Lobinden.

You must speak to Dandelion after the rose of remembrace quest I believe.
The Wild Hunt - Acquiring all the Journal Entries

The conversation with Dandelion after triggering the flashback, after talking to Ciaran, I don't know how to reliably acquire. It adds a unique journal entry, but I don't know what you must (or must not) do prior to talking to Dandelion. As I mention in the thread I linked to above, my only theory so far is to not talk to Dandelion at all, prior to triggering the flashback of the Isle of Avallach (interrogating Ciaran).

The manuscript of Morten Collis is found in the catacombs outside Vergen, during Chapter 2. It's in one of the wrapped-up corpses. Showing this to either Philippa or Síle, will enable you to talk to Cynthia or Myron about this script; you can also later, after getting the flashback about the Ravine of the Hydra, show it to Dandelion, but he falls asleep because it's so boring. He is instead more interested in the Song of the Hunt - once you've found this book, and have the Ravine of the Hydra flashback trigger, have Dandelion interpret the poem for you. As far as I know, this can only be done if you're on Roche's path, however, probably due to a bug. I opened up the topic I linked to in an attempt to decipher the different requirements for unlocking all the journal entries concerning the Wild Hunt.
The dialogue is probably blocked then. =(
Rato: The dialogue is probably blocked then. =(
Aye, I've only had that conversation once. Going to start a new playthrough soon, and I intend to try out the theory I have of not speaking to him before I get the Isle of Avallach flashback.
Going there and talking to him just after the quest doesnt do anything, because i did that even without knowing he would give me a dialogue option. So i think your theory is right and if it is, it sucks anyway.