Awareness campaigns

Perhaps I am an idiot (and that is very much a possibility) but I don't understand the point of campaigns to raise awareness of very well known diseases. In my time I have seen skin cancer, diabetes and HIV/AIDS awareness campaigns, among others. Is anyone not aware of these problems?

I could understand awareness campaigns for Acrocephalosyndactylia, Enchondromatosis, Histiocytic Necrotizing Lymphadenitis, or Waldenstrom Macroglobulinemia (four diseases I just found on wikipedia's list of rare diseases), but not the usual ones that get the campaigns.

That is all.