Colin Farrell says being a father is more important to him than his career.

The 'Artemis Fowl' star - who has sons James, 16, with Kim Bordenave, and Henry, 10, with Alicja Bachelda-Curus - finds raising his children much ''harder'' than acting but even though he enjoys his work, it's ultimately far more fulfilling.

He said: ''My kids are my masters. They bring up a lot of fear and self-judgement in me. Having kids is the most important thing in my life. This whole acting business is nothing in comparison.

''Don't get me wrong, I know I'm one of the fortunate people who gets a certain amount of meaning from my work. And, self-indulgently, I sometimes get off on what I do, but being a dad to these two boys is the most difficult, the most rewarding, the most meaningful and the most consequential thing that I will ever do by far.

''I find parenting a lot harder than acting, as I think I should.

''As an actor, we get to explore humanity and to express ourselves creatively - and you get to make the money you get to make. But the real business of living is all to do with being a dad. Fatherhood is very important to me.''

The 44-year-old actor admitted he doesn't ''know what [he's] doing'' when it comes to raising his sons and his biggest parenting aim is not to ''f**k them up'' too much.

He told OK! magazine: ''Fatherhood has changed me completely. It changes me every day. I don't know what I'm doing most of the time - or all of the time - but I adore my boys. I love them very much.

''To be honest with you, I just hope I'm not f***ing them up too much. If all of us can f**k up our children a little less than we were f***ed up by our parents, then that can be the bar for success.''