attention

You are blind to changes in the scenery.

A 1998 study showed that participants often failed to notice if a conversational partner was replaced by a different person mid-interaction.

The study demonstrated change blindness to the identity of the person, which is a more significant oversight than a mere change in clothing.

You assume you are tracking the world far more closely than you actually are.

Where this comes from

Study: Simons & Levin, 1998
What the check found: The actual study (Simons & Levin, 1998, 'Failure to detect changes to people during a real-world interaction') focused on the substitution of one individual for another, not just a clothing change.
Confidence: Solid, with limits

One of these every day, and every one names the study it came from. When a finding is contested, it says so.