Nobel laureate Seamus Heaney was bemused by the critics' response to his latest collection of poetry.

It wasn't that they didn't approve--in fact he acknowledges that Human Chain has been received positively.

But Heaney admits he had not realised the theme of approaching death had featured quite so prominently until they pointed it out to him.

"I didn't have such a strong sense of mortality running through the book until the reviews began to appear.

"It daunted me. I thought, this sounds like he's writing his own obituaries," he laughed.