vision

It is physically harder to look back at things.

Inhibition of return typically manifests when the interval between a stimulus cue and a target exceeds approximately 300 milliseconds.

The effect is a reversal of initial cuing facilitation that develops over time, not a discrete delay triggered exactly at 300ms.

Your attention system is engineered to prioritize novelty over thoroughness.

Where this comes from

Study: Posner and Cohen, 1984, Attention and Performance X
What the check found: The claim mischaracterizes the timing of the effect. Inhibition of return begins to appear when the interval exceeds roughly 300ms, rather than being an effect caused specifically by looking 300ms ago.
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.