If you rewatch the scene where the Author stops his opening narration to snap at his son, you can see him trying to ignore his son entering the room off screen a few seconds before he finally breaks down.
The stylistic visuals of the film actually help to enhance the narrative, which is a flashback plot. We're seeing the memories of Zero and of others, not necessarily as they happened but how they were experienced.
The Author's last scene features a painting of mammoths. Mammoths are majestic creatures of a bygone era who passed on, similar to the Grand Budapest Hotel and its cast.
When you stop and think about it the only happy time of Zero's life was a short period where he worked as a Lobby Boy at the hotel despite putting in 100 hour weeks and going on a dangerous adventure. But otherwise his entire family was murdered, he had to flee his home as a refugee. His mentor (and substitute father) was murdered in front of him. His wife and child both die. He had to give up the fortune he inherited to save the hotel, and it ultimately loses its' grandeur and is demolished anyway.
