What is the most common subject that song writers use?

would the subject matter very on who wrote it and who perform it? It seems that the subject matter is divided within the genres.

Some discribe rap as a poetry told by individuals who have experienced hardships.

Pop sounds like the subject matter of the average teen -- boys, falling in love, crushes, country tells the listeners stories and experiences but more down to earth,

r&b and soul-- romantic love, dance, partying,

rock-- part rebellion, rougher edge then pop

metal -- numeruos subjects but it seems to not follow the paved guidelines of a practical song. but it has its own sound, like individualism.

blues-- morals, truths of diiferent degrees

if i missed any i do apologise.