But I thought that the Brit opinion was that "American culture" was an oxymoron(?) - hardly worth asking about.

Most of the "inscrutibles" I encounter here seem to arise in "clique" subcultures, particularly in those who adopt bizarre behavior and language in a deliberate attempt to isolate themselves as a distinct(ive?) ethnic (or gang) group. Attempting to understand would be "intrusive." The slang that makes it into mainstream use gets into the international market so quickly that young Brits probably know it better - and sooner - than older 'mercans.

John