The speaker feels that anything that brings them peace eventually disappears. The opening lines state this plainly, and the single word "leaves" sits alone on its own line, so the loss feels sudden and final.
From there the speaker turns to a bitter kind of wish. If comfort always leaves, then perhaps they should look for comfort in the opposite things: lonely nights, broken hearts, sad smiles. If those become the source of peace, maybe those will leave too, and the pain would go with them. The repeated "just maybe" makes the idea sound tentative, almost like a quiet joke the speaker only half believes.
The mood is tired, hollow, and resigned. There is no anger here, only a worn-down logic that comes from being left too many times. Beneath the dark twist is a plain hope: that something, someday, will finally go away and take the hurt with it.