Dangerous Minds

Dangerous Minds is a main story quest and achievement/trophy in Fallout 4.

Lounging around at the Memory Den
After killing Conrad Kellogg, loot the cybernetic brain augmenter to delve deep into his memories. Gather it from Fort Hagen (as part of the previous quest, Reunions) if it hasn't been taken already.

Follow Nick Valentine's advice and locate Doctor Amari. This involves a trip into Boston, through the ruins of the Financial District, to the rough-and-tumble fortified settlement of Goodneighbor. Greet the locals, then head to the Memory Den, owned by Irma.

Down in the basement, converse with Doctor Amari. After Nick Valentine volunteers to help out, the Sole Survivor is invited to sit in the lounger to experience snippets of Kellogg's past.

Memories
The Sole Survivor wanders through the ethereal strands of Kellogg's memory. Stepping from memory to memory, scenes play out revealing pieces of his life. In most of the memories, various things can be activated to trigger additional monologues, where Kellogg will go into more detail about them.

The memories reveal that Kellogg does indeed work for the Institute, took Shaun from Vault 111, and that they use some kind of teleportation to operate freely. The final scene reveals that Kellogg's current mission is to hunt down a runaway scientist named Virgil, who likely escaped into the Glowing Sea.

Back to reality
Upon conclusion of the final scene, Doctor Amari will instruct the Sole Survivor to interact with the television to leave the memory. Back in the Memory Den, speak to Amari about Virgil.

When leaving the Memory Den, there is an optional conversation with Nick Valentine where he will first seem to have been taken over by Kellogg's memory, only for Nick to seemingly regain control. He will also offer additional advice about hunting Virgil.

Quest stages
This quest branches into an unmarked subquest, Shattered.

Companion reactions
Every companion except Curie likes when the memory playback is completed. Curie is indifferent, and Nick is always present for the event to trigger.

Behind the scenes
The radio announcer in Kellogg's childhood scene in the NCR is voiced by Fallout 4 lead designer Emil Pagliarulo. The bartender in the bar scene is voiced by Veronica Cartwright. The two wastelanders are voiced by Brandon Keener and Bruce Thomas. The agent at the desk in the Institute scene is voiced by Misty Lee.

Bugs

 * Rarely in the same scene, one can pick up one of the first two rifles dropped and keep it after exiting if it spawns with non-standard modifications.
 * Shortly after finishing exploring Kellogg's memories, the objective may not register as complete. A door icon will be seen underneath Doctor Amari's office and is inaccessible. Reloading a previous save seems to be the only way to fix this.
 * This bug may be triggered by picking up the Institute synth weapons during the memory sequence. Reloading the save and not picking up any weapons during the memory sequence should prevent it from triggering.
 * While exploring the memories, sometimes, (seen during the wastelanders' kill request memory and later) even after the end of exploring the area, the screen will freeze and Kellogg and the environment will not move or talk, but the player is able to proceed further and explore the other memories.
 * If one wishes to watch the memory that has been frozen, they may simply walk back to the path of the brain that led them to the memory, then walk back into it. This will cause the scene to continue to play out.
 * If Nick has power armor equipped during this quest after he exits it, all parts will be marked as owned.
 * On PS4 there can be a glitch going through Kellogg's memories that will not let the progression continue.
 * To fix this load a previous save prior to sitting in the memory lounger.