Mueca translates to "grimace" or "wry face." It's a less common word than
This song is a powerful declaration of letting go. The singer paints a picture of someone they can't forget, describing their "sad and spectacular face" and their skin that seems "immune to sincerity." This person has left a permanent mark, like a "nail in the wall / That I can't take out" or a painful thorn that won't stop bleeding.
Despite this lingering pain, the singer makes a firm decision. They declare, "I won't wait for you anymore," setting this resolution at the symbolic "borders of the capital." It's a moment of accepting a hard truth: the other person is not coming back. The singer decides to move forward, concluding that it doesn't matter what anyone else thinks about their choice.