One of my favourite amusements when reading a book is recognising quotations the author has woven in. Older books did this a lot (I'm thinking of Anne Hepple's Border romances, for instance), mostly quoting bits of poetry or Shakespeare's plays (Georgette Heyer had her hero in "The Black Sheep" quote "my bright particular star" to the heroine and years later I remember the quotation though the hero's name? oops, gone completely).
I was wondering if this has gone out of fashion, but then I realised the shared background of author and readers is less poetry now than the pop culture of TV, movie, music--and this has two drawbacks. First, the copyright and permissions issue. Rather than deal with the hassle, authors don't use the quotations. Second the fact these references have short life spans and quickly date a book.
I understand all this but...Bring back the hunt-the-quotation game!