Maybe you see a plant you have to collect in game or a rock wall that looks different. What items have you caught out of the corner of your eye that you realized was just your brain so focused on looking for things in a game that you saw it IRL and made you double take?
If you play The Witness, this will permanently happen to your brain - you’ll start seeing
spoiler
environmental puzzles
everywhere
mmmm biscuits
Yep. Haven’t played in years but I’m still spotting them.