Livre d'Or

I think my example of my work colleague isn't really "agreeing to disagree", it's me unilaterally deciding not to argue. I know there is a disagreement; they probably don't.

There are social and personal costs to arguing and to speaking up, because usually the person speaking up gets tagged with the Being Awkward label not the person saying the thing being challenged. The calculation is made, whether consciously or unconsciously, about whether any benefit resulting will be worth the cost.