I found this expression the other day :
I failed to get what it means and looked for its meaning on the Google translate and it told me that the meaning of this sentence is : "I can't believe it". I didn't feel sure thus trying other translation machines but the result is the same, they all told me that "我简直不敢相信！" means "I can't believe it".
The question is... I don't get it how that sentence means "I can't believe it". Especially the "(不)敢" part. What does it have anything to do with "I can't believe it"?
Also, why is it not written as "我不能相信它/这个"?