Colleges Online Classes in Distance Education Degree Program

I am a native English (American) speaking male (24 years old).
From Georgia.

I studied French in high school, however, I remember NONE of it. I actually got a D in the class, becuase frankly I didn’t try.
Anyway, in college, I was required to take a significant amount of foreign language courses.
Again, I didn’t try much on the assignments, but I did pick up a lot of Spanish.

I can not speak Spanish for the life of me, but I can understand around 40% of what I hear and I can read it even better.

Basically Spanish wasn’t that difficult of a language to pick up on as a English speaker.

Regardless, I want to learn some Mandarin/Chinese. I purchased the Rosetta Stone program for Mandarin. It has the 3 levels.

I have also ran through some online lessons (like http://www.chinese-tools.com/learn/chinese), but I am just dumbfounded.

I am not dull and have proven that with my academic success (ignoring the fact that I didn’t try in highschool).

It really seems as difficult is learning a new language could get. Is learning Mandarin as a native English speaker really as difficult as it appears to be, or is it just a “it just needs to be presented to you in the right way” type of thing.

How would you rate the difficultly of learning mandarin on a scale of 1-100, for a native English speaker using learning Spanish as a standard (rating of 50 on the same scale). Where 100 would be, no other language would be harder to learn.

Frankly, I rarely encounter something I am not able to pickup and learn with little effort. However, Mandarin just isn’t sticking.