This achievement is awful: it requires you to complete the game in the most inept way imaginable, asking the cat for every possible hint. Hints are only available at specific, limited points in the game. Took me multiple tries and I doubled my total playtime trying to get it.

1. Download this save file I've posted to dropbox:
   
   https://www.dropbox.com/s/mcmi6wxysmbt16y/savegame03.dat?dl=0
2. Navigate on your local drive to the save game directory
   
   C:\Users\<user>\AppData\Local\Dude Where Is My Beer\Dude Where Is My Beer\Savegames
3. Make a backup copy of the save files that are in the directory above.
   
4. Remove any save files in the directory above.
   
5. Move the file you downloaded from dropbox into the directory above.
   
6. Might want to disable cloud sync by right clicking the game in your Steam library and fiddling with properties.
   
7. Launch the game.
   
8. Go to options and select easiest difficulty. (Not sure if this if required.)
   
9. Load the save file, and play.
   
10. Walk out the door on the left.
    
11. Spam the ending dialogue. (Spoilers).
    
12. Get achievement.
    
13. Sit through credits.
    
14. Quit game.
    
15. Replace save files if you want and turn cloud sync back on, or uninstall the game and never look back.

Thanks to:

• TheDeluxeTux's guide, which helped a lot,
  and
  
• aquatorrent's list in the forum, which helped even more.