The 44-year-old 'PS I Love You' star lost contact with his father Edward after the family emigrated from Scotland to Canada when he was a child, reported Contactmusic.
The actor's new animated movie features a reunion scene in which his warrior character Stoick is brought back together with his long-lost wife, and Butler reveals he intrinsically knew what to do because of his own experiences with his father.
"(Stoick) is remembering the days when they were falling in love and it's a very moving scene. It is interesting for me because for 14 years I didn't see my own father. I didn't even know he was alive. I just understood that scene from the second they gave it to me. I knew what to do," Butler said.