What does the author mean by nobody knows and somebody Miss in letter from Birmingham Jail?

In "Letter from Birmingham Jail," Martin Luther King Jr. emphasizes that "nobody knows" the full extent of the struggles faced by marginalized communities, underscoring the ignorance of those who have not experienced systemic oppression. Conversely, "somebody misses" highlights the responsibility of those who are aware of injustice to act and advocate for change. Together, these phrases illustrate the need for empathy and action in the fight against social injustice.