Tell me about your experience learning Mandarin

Hello students of Mandarin,

I am writing an article about my experience studying Mandarin.  At this time, I mainly use online resources, including yoyochinese.com, various youtube.com teachers, and I watch Chinese and Taiwanese dramas (soap operas).  I practice the Pimsleur tapes when I walk my dog.  

Please reply and tell me how long you have been studying Mandarin, how old you are, and what has been helpful for you in learning the language.  What has been the most difficult thing about learning Mandarin?