If my statement is:

{

        Comparing cantonese and mandarin is like comparing norwegian and danish.

}

Then would my statement be true?

In most cases, NO. But I do, for I can speak both. Phonetically, Cantonese is close to the dialet used 1000 years ago (Song dynasty), many people fled to the south due to war. So it is kept to nowadays. Mandarin is used in the north of China, it has changed a lot since Song dynasty due to war with Mongolia and other minorities. When foreigners became rulers, they brought new words and made Chinese pronounciation easier for themselves. Gradually, pronounciation and language changed greatly. In this case, poems in acient times sounds nice and perfect in Cantonese but worser in Mandarin. The difference is so big, that native speakers from two areas cannot understand each other totally. Since Chinese is not alphabetical, they can communicate with written Chinese, yet still not the same.

Cantonese is a kind of dialect, not a foreign language, so I don't think it is too difficult to understand. Watch some tv shows/ dramas or movies in Cantonese with Mandarin subtiles for a few months, and I am sure that you will figure out the differences between Mandarin and Cantonese, and get used to Cantonese soon.

I'm afraid not.

I speak both though because I was born in Guangzhou where both languages are used.

Not only the structure but also the pronounciation of Cantonese are like that of ancient Chinese.It isn't proved officially but many people including me have found that more ancient poems rhyme in Cantonese.

It's difficult for Cantonese speakers to pronounnce Mandarin correctly,and it's difficult for Mandarin speakers to understand Cantonese too.A few of my classmates speak little Cantonese but they usually understand us.