Rihanna is talking about trying to move on from a break up with someone you truly loved, but she is still suffering, such as when she says "I shouldn't be crying, tears were for the weak. The days I'm stronger, know what, so I say that's something missing." No matter how much she is trying to move on, she still misses him and feels incomplete. From my own experience, I know the feeling of grieving, confusion, and depression after a break up, no matter how long ago it was. You still try to live your life though. Rihanna is really opening up in this song because in this stage of a break up, you don't want people to know you're suffering because you should be over the person, so you keep all your feelings to yourself and have people believe your facade while you cry yourself to sleep every night.
Rihanna is talking about trying to move on from a break up with someone you truly loved, but she is still suffering, such as when she says "I shouldn't be crying, tears were for the weak. The days I'm stronger, know what, so I say that's something missing." No matter how much she is trying to move on, she still misses him and feels incomplete. From my own experience, I know the feeling of grieving, confusion, and depression after a break up, no matter how long ago it was. You still try to live your life though. Rihanna is really opening up in this song because in this stage of a break up, you don't want people to know you're suffering because you should be over the person, so you keep all your feelings to yourself and have people believe your facade while you cry yourself to sleep every night.