A.K.A. the thing that people are still sensitive or insecure about, or feel the need to correct or overcome. A historical grievance, an ongoing issue, a cultural stereotype, etc.
For Portugal, it would be how irrelevant we are compared to the 16th century, or the fact that everyone confuses us with Spaniards or Brazilians. (Though it’s not as intense now that we’ve become a popular tourist hotspot.)