After Kurse kills Frigga, Odin rushes to his fallen wife and begins to mourn as he holds her corpse tightly in his arms, whilst Thor just stands there behind him with a disinterested demeanour, as if she were just another random Asgardian warrior that had fallen to the enemy. By watching the scene you'd think that she was not his mother at all.
Even Loki, Thor's evil and murderous brother whom killed dozens of people and attempted to conquer Earth in Marvel's 'The Avengers' reacted in they way you'd expect a son to act upon hearing of his mother's death. Why was Frigga so insignificant in Thor's eyes?