Simplify the following text for a Grade 12 native English-speaking person.
Original: The poet has commented on the fact that his parentage thus contains both the Ireland of the cattle-herding Gaelic past and the Ulster of the Industrial Revolution ; he considers this to have been a significant tension in his background .
Simplified: Heaney said it was important part of his background that his parents came from different parts of Irish life : the cattle-herding Gaelic past and the Ulster of the Industrial Revolution .