The brain is evidently really good at identifying things that it likes or dislikes when it’s presently sensing them.
However, my brain in particular seems to be really bad at recognizing things that it’s missing. I get a vague feeling of “Hmm, I miss something, but I can’t quite put my finger on it…”
After some thought, I think I’ve figured it out. I miss winter and the smell of pine trees. Living in the desert, I don’t really have many pine trees around, and I miss that.