Kit Harington is finding new things to appreciate about parenthood every day.
Speaking with Access last week, the Modern Love actor, 34, gave rare insight into his life as a new dad, sharing what has surprised him most about fatherhood. PEOPLE confirmed in February that Harington and his wife, Game of Thrones costar Rose Leslie, had welcomed their first baby, a son.
"I think the thing that's surprised me most is, you know, they tell you but they don't; everyone goes, 'Look, it's big. What you're about to go through is big.' And you have no way of knowing that until it happens," he says. "Then what surprises you is you go, 'Oh, this goes on forever!' You don't get a break from it. You're just like ... every day I wake up and look after this little human and now we're part of a unit together."
"You are now a unit, the three of you," adds Harington of his family. "That's a whole new dynamic you need to find, and pretty much find every day as he grows and changes, and how does that change you? It's a beautiful thing, it really is."
The actor also noted that they got a puppy in the year leading up to their son's birth and "it's not so different" than raising a newborn baby. "It's great practice, is all I can say," added Harington.
Want to get the biggest stories from PEOPLE every weekday? Subscribe to our new podcast, PEOPLE Every Day, to get the essential celebrity, entertainment and human interest news stories Monday through Friday.
Leslie confirmed their pregnancy in September after she debuted her baby bump for U.K.'s Make Magazine and spoke about how the couple has been spending quality time together in their Tudor manor house in East Anglia amid the pandemic.
Harington previously shared that he was ready for fatherhood. Ahead of the May 2019 series finale of Game of Thrones, the actor told InStyle: "The most important job I'll ever have is about to finish. Well, not the most. Hopefully, I'll be a father."
RELATED VIDEO: A Baby Boy! Game of Thrones Stars Rose Leslie and Kit Harington Welcome First Baby
He and Leslie famously portrayed star-crossed lovers Jon Snow and Ygritte on the Emmy-winning HBO series Game of Thrones and first stirred up relationship rumors in 2012. After a brief split, they reconciled and continued to fuel romance speculation until they officially confirmed the relationship in April 2016.
They got engaged in September 2017, confirming the happy news the old-fashioned (and very British) way: through a classified advert in The Times. Less than two years later, they wed in Scotland in June 2018.