If there's nothing more exciting to have for lunch (leftovers, treats, etc.), I tend to have a fake-chicken slices and cheese sandwich and some crisps/chips.

I do this a lot. I did it today: getting the bread and plate out of the cupboard and the cheese, mayo and "chicken" out of the fridge, assembling the sandwich, cutting it in half, putting the fridge stuff away...

It was a busy day at work so I was eating at my desk. Perhaps this contributed to me getting more than halfway through the sandwich before I realized that I hadn't put the cheese on it.

It was a new package of cheese and I didn't even notice that I put it back in the fridge unopened!

This right here is Seasonal Affective Disorder for me; it's not "I'm a bit sad haha" (though my mental health is in the toilet this time of year too), the real problem is that nothing I can do gives my body the energy to make a sandwich I make all the time, to notice the absence of one of its two ingredients.