It's mostly common knowledge that people with Aspergers are devoid of emotions. It's also a common misconception. Most Aspies do experience a range of emotions from sadness to joy. The misconception stems from two places:
1) Aspies have difficulty expressing their emotions in the "socially agreed upon" manner.
2) Aspies very often experience emotions in extremely polarized states with no middle ground.
Reason 1 pops up because, although Aspies are good mimics, people will often express their emotions in slightly different ways. Some people may cry at the death of a loved one, others may throw themselves into charity work, and others may react in a different way entirely. While each of these reactions share an underlying theme of grief, an Aspie may see these three reactions as random and unrelated - they don't make sense. Therefore, it's tough for an Aspie to figure out the "correct" way to express an emotion.
Reason 2 sounds like all Aspies are bipolar, but that's not what I mean. The emotions don't necessarily wildly fluctuate from one extreme to another. It just means that the "low intesity" emotions are too weak for an Aspie to register; the Aspie brain is usually too busy with other stuff. A strong enough emotion will break through. For example: I find it almost impossible to "like" things. Either it's really bad and I hate it, or it's really good and I love it. Anything else, and I don't really have an opinion one way or another.
I think emotions are so difficult for a person with Asperger's to deal with because emotions are not a tangible entity. My mind works sort of like a mini-computer; it deals it facts and figures. Computers don't understand emotions because they can't be calculated. I'm often asking how I "should be" feeling in a situation because I honestly don't know. I have a theory on how I "should be" feeling based on past experiences and popular social customs, but I can never be sure.
So don't think that us Aspies are all just soulless, disconnected people. We do have hearts. We do have emotions. They just confuse us immensely.