I don't need to learn. Everyone around me speak Mandarin. Cantonese is commonly used in southeast China. So quite an easy thing~Though my cantonese isn't standard.
The resaon why i would like to learn cantonese is that my parents can speak mandarin and cantonese. I can only speak mandarin and that not so good. That's why i want to learn Cantonese to surprise my parents :). And i think, Cantonese language is more beautiful than Mandarin.