My friend said, 'This is the most obscure thing I’ve ever heard of.' I said, 'What is it?' He said, 'The 1990s.'

My teacher said, 'This is a very obscure reference.' I said, 'What is it?' She said, 'I don’t know.'

My friend said, 'I know something no one else knows.' I said, 'What is it?' He said, 'I don’t know.'