In my opinion this song is about on-sided love, that hurts the narrator because the other person only uses their feelings and plays with them (“I’m tired of being played like a violin”.) The narrator is head-over-heels for the other one. They put so much effort into this relationship (“And I tried to buy your pretty heart/ but the price too high”) and are left with nothing else to give (“What do you want from me?”) as the other has treated them in such a bad way (“So you can put me together/ And throw me against the wall”) and has exhausted them emotionally. However, the narrator’s love towards the other mentally abusive lover is so strong that they are “fisting with fire/ just to get close to you”. This love is so strong yet so tiring, probably both mentally and physically, (“And I run for miles just to get a taste”). The narrator is desperate for the other’s love, attention and appreciation and even though it hurts them, I believe it’s more of a mental pain that this song is about, (“It beats me black and blur/ but it fucks me so good”) they are so intoxicates by it that they “can’t get enough” and it keeps reminding of itself all the time, probably by dreams, memories, ect., (“And it keeps cursing my name”) that all effort the narrator puts into forgetting the other one is basically pointless, because the need and the wanting are stronger that their will to get over it. All the narrator asks for is for the other to love them and to stop this mentally abusive relationship (“All you need to do is love me yeah”). This love that has savoured the narrator is in their brain and this is the only reason why they cannot get over it, becaue biologically all feelings are commanded by it. Hence the “Must be love on the brain” lines which state the narrator’s helplessness in the situation and their lack of control over their feelings which get us to one of the most emotional parts (“What do I gotta do to get in your motherfuckin’ heart?”). The narrator’s lack of control means that they have to somehow cope with the situation and since this feeling is so strong this line states that they are willing to do everything to win the other’s heart, regardless of how hard and emotionally draining it may be. The narrator is already broken and the last thing left for them to do is try, and try harder.

Although this song might be dedicated to Rihanna’s abusive relationship with Chris Brown, I believe that it is more emotionally related, since it has affected the brain (where all emotions are conveyed).