Even so "getting 21 years" for this crime doesn't accurately give the full story. Consider Charles Manson. His life sentence really isn't since he can be released on parole. I could make a thread about that and go off on the system and not make a single false statement. I wouldn't because I know it would be illogical considering full context. He was up for parole, again, and to no ones surprise didn't get it. In norway the sentence isn't open ended but terminates unless the criminal is still seen as a threat, like Manson. Out really isn't all that different if one steps back and looks at the actual process.
And from some quick googling it looks like Manson ended up eligible for parole after only 7 years.