If you saw one of the mysterious monsters, it would reveal your biggest fear, and you’d either kill yourself or — if you were already mentally unstable like Gary — you’d becoming an evangelist for the creatures and try to force everyone to see.
Bird Box memes were everywhere about a month ago.
The #BirdBoxChallenge seemed to pop up out of nowhere, with fans trying to mimic the film (and book’s) conceit of needing to shield your eyes through everyday life.