But it doesn't end there.
This works for everything. Our brains seem to have a penchant for more of the same, even if it's something negative.
If we are already bored we find things more boring.
If we are already sad we find things more sad.
If we are already frustrated we find things more frustrating.
If we are already scared we find things more scary.
If we are already annoyed we find things more annoying.
If we are already worried we find things more worrying.
There are no exceptions to this rule. Simply, if our coping systems are already stressed, we find things more stressful.
It's a cycle, or really a spiral, downwards. It can be broken, but that requires some delightful stroke of luck, of random intervention, or for us to be aware of what is happening, and pull ourselves together. However, there can come a point where it take a considerable effort to reverse it.
Of course, the good news is that it works the other way too.
If we are already pleased we find things more pleasing.
If we are already excited we find things more exciting.
It takes a lot of the positive to counteract the negative, and the amount required increases the further down the negative spiral we go.
But most importantly, we are deceived by this.
If you are in a bad mood, a very minor irritation can seem like a very big deal. This is why tired, grumpy people "snap". We've all done it. We've all reacted out of frustration at the end of a bad day. It takes quite a lot of deep breaths and counting to ten to tolerate annoying things when we are at that point.
But when we are having a good day, we might take the exact same "issue" in our stride. Therefore, we are deceived by our negativity into thinking something is awful, unbearable, bad, when our rational mind knows it's no big deal at all.
The negative mind is not a rational mind. Grumpy people are not realists, they are suffering.