"Unsettled" is a word most of us know. It is used in numerous contexts, with nuanced meanings for each.
Sometimes debts go unsettled, creating dissonance between borrower and lender. Sometimes social contracts get violated, leaving an unsettling dissonance between the parties. Sometimes we get an unsettled feeling when expectations we have for others go unfulfilled, thus creating discontent and dissonance. Sometimes the forces of Mother Nature create an unsettled environment, foretelling a storm or significant weather event, thus creating atmospheric dissonance.
In virtually all circumstances of unsettledness, an imbalance exists. Either the laws of nature or our intuition or our moral compass tells us that something is a bit out of whack and needs to be returned to some semblance of balance before the dissonance can be mitigated.
When we fail to express love, affection, and appreciation to those who have positively impacted our lives we get that unsettled feeling deep down inside. And should.
We can, at very little cost, correct that imbalance and the accompanying dissonance. And should.