Based on the original music video, we can probably conclude that the song directed at the something missing between two lovers, stating that if one of them doesn’t open up on their identity, the relationship is pretty much screwed.
Considering that the only “relationship” (if you can even call it that) is between me and my 2kg organic chem textbook after I broke up with a real person, I’ll have to tweak the meaning to fit me: Instead of the song discussing emotional distance between two people, it would discuss a person who likes the subject but just “doesn’t get” orgo and can’t run any reactions, whether on paper or in the lab. As a result, the person is desperately holding on, trying his or her best to not fail and need to retake the class.
I guess the relationship between a student and his/her chem textbook and the relationship between people is pretty similar, though I would prefer to use the analogy of being a teacher and needing to know all the students and faculty. Each person is different and has their own group of friends, just like each compound is different but has specific functional groups (alcohol, aldehyde, ketone, etc), and the groups function similarly. As a result, after understanding the people/compounds, they would be able to predict “what happens next.”
However, textbooks don’t eat your food. They don’t obnoxiously text you when you want to stay in binge-watching 10 years’ worth of ESC contests. And considering that I can’t really talk to people, I’ll keep the textbook. At least until the semester’s over.