Here is my 100% Achievement Guide for Tell Me Why.
When you first enter the Ronan household, from where you start, you see a door on your left with 3 wooden circle puzzles on it.
You cannot interact with it yet, you need to first go upstairs, go into Tyler's and Alysons room (first door on the left as soon as you get upstairs.. its slightly ajar)
Interact with a book on the desk and watch the ensuing memory.
After this we can head back downstairs to Mary Anns room and do the puzzle.
The solution is in the actual book but if you want to just have the solution it is:-
Moose - Bear - Pelican
(Note, you can miss this by breaking down the door so I suggest to not do that lol)
Go to 39:45 in my video to see the start of it
Hope this helps!