"My father has delivered over 6000 babies, my stepmother's an obstetrician gynaecologist and I've been around a lot of baby talk in my life.
"But still, nothing actually prepares you," he later added to the UK's Stylist.
"I hope I'm a good dad. It's the most joyous thing imaginable. It's totally changed our lives but only for the positive.
"People are so f**king down about having kids - in those early months when people are saying, 'Say goodbye to sleep.' Well, of course! You've got a baby!" he continued.
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"I was discouraged by people's attitude so it was refreshing when we occasionally met people who said, 'It's the best thing, you're going to love it'.
"I saw a pregnant friend the other night and I was like, 'Embrace it! Don't listen to all the people who are down on it, because it's only good'," he added.
Dornan wed Warner in April 2013.
- AAP