The ordinary day becomes precious when its circumstances cannot be repeated.

Value often becomes visible only once repetition stops. A Tuesday with everyone in the house, nothing planned and nothing remarkable said, is worth little while such Tuesdays are plentiful. When the arrangement changes, and people move, or fall ill, or simply grow up, the same day becomes something you would pay a great deal for. Nothing about it was ever unremarkable; it was just abundant.

You cannot make yourself feel this in advance. What you can do is decline slightly more of what would take you out of the house on an ordinary evening. Not because it is running out, but because the plain version is the thing itself.