By sheer fluke I read this today. In Hugh MacDiarmid's The Company I've Kept there is a conversation between him, John Ogdon and Ronald Stevenson about Kaikhosru Shapurji Sorabji (who MacDiarmid knew very well for most of his life). Stevenson says this (thinking about the quotation of folk tunes by art music composers):

Dozens of phrases from Shakespeare have been absorbed into common parlance in Britain; the same can be said for Dante in Italy; the difference is that in Britain most people don't know it's Shakespeare they're quoting, whereas in Italy they do know it's Dante. A few years ago, on O'Connell Bridge in Dublin, an Irish tramp quoted Yeats to me. I said, 'Could you direct me to the Abbey Theatre, please?' and he replied, correcting me with kindly reproof, 'You mean Yeats's theatre'; and he proceeded to quote Yeats to me.