That's exactly it - we notice and respond to differences. See https://en.wikipedia.org/wiki/Just-noticeable_difference https://en.wikipedia.org/wiki/Just-notice

That's exactly it - we notice and respond to differences. See https://en.wikipedia.org/wiki/Just-noticeable_difference https://en.wikipedia.org/wiki/Just-noticeable_difference Once those differences have been normalised we stop feeling the same way about them, and become attracted to other things just because they are novel. This is why it's often better to call a mix 'done' before you start believing it's completely wrong and tearing it apart again, only to prefer the old version.