This page contains a detailed walkthrough for Dear Future Self, one of the more complex achievements that involves finding and listening to all messages recorded by Morgan Yu before his memory loss.
Notes - Each recording (in all, 11 messages) has to be listened to manually in order to be counted towards the achievement. This is especially important in case of TranScribe recordings.
Acquisition of Recordings 1-3 is mandatory, and takes place during certain story quests (An Office with a View, Through a Glass Darkly, Before I Give You the Key). Each one of these missions sees you interact with the Looking Glass console and download a 3D recording.
Recording 4/11 (I keep Having This Dream) is stored on a TranScribe Device found in a hidden safe inside Alex Yu's Office in Arboretum. The safe is hidden in a side room that can be accessed by moving a crate (Leverage II) or by breaking through the Looking Glass screen on the other side of the office (Getting access to the safe is a part of Who is December? - see the dedicated section for a more detailed walkthrough). The safe itself can be accessed through Hacking or by using a code received while exploring Psychotronics during Detour.
Recordings 5-10/11 take form of short memory logs that can be found on Morgan Yu's station in his apartment found on level 3 of Crew Quarters. Each recording is a short comment on a different inhabitant of the station.
Warning - Listen to each recording BEFORE you complete The Keys to the Kingdom, as the final part of the quest begins a showdown that blocks the access to Crew Quarters.
Recording 11/11 (If Things Go Sideways) is stored on a TranScribe found in Alex Yu's panic room in Arboretum. The opportunity to get the recording appears in the final phase of The Keys to the Kingdom. Talk to Alex and descend to his dwelling to find the final recording which is lying on the desk.