You may remember where you sat longer than what the argument settled.

The room outlasts the resolution. You can recall the chair, the light, who was opposite you, and be entirely unable to say what was decided or why it mattered so much at the time. Setting is easy for the mind to keep and reasoning is not, so the container survives and the content goes.

After anything consequential, write the conclusion down in one sentence the same day. Not the discussion, just what was decided. It is the part you will lose and the part you will need.