Ganzfield effect 

A hallicunitory effect that occurs when the brain cancels out any visionary or auditory signal, resulting in mass hallucinations similar to that of LSD. It is typically induced by slicing a ping-pong ball in half, and placing one half over each eye. One then fills the room with blank radio static, and shines a red light through the ping pong ball.

I just saw a unicorn via the Ganzfield effect

Ganzfield effect by shitmotherfucker July 25, 2014

The Garfield effect 

When you begin to look for Garfield, you begin to see him everywhere. For example: You see a Garfield plushie in a store or on a T-shirt someone is wearing. Garfield has bacome so mainstream over the last 40 years, that we have subconsiously erased his image from our life.

Person1: "Dude here he is again, Garfield!"
Person2: "You're just crazy, he isn't everywhere."
Person1: "I'm telling you, it's The Garfield effect."

The Garfield effect by Xrendr July 1, 2023

The Garfield Effect 

when you feel tired and off purely because it's a monday

Person: Aw man I'm suffering from The Garfield Effect today
Person2: Oh dude that sucks

The Garfield Effect by vimwit March 1, 2021