Hmm, I think it is less than productive to suggest all people with asperger's lack empathy, simply because you believe you lack empathy. I am trying to wrap my head around how you can think it is logically consistent to hold that view along with the view that another person cannot understand something unless he or she has experienced it. After all, aspergers for you is different than aspergers for so-and-so, thus (according to your reasoning) you cannot speak for that person. How can you say he or she doesn't have empathy. Moreover, how can you say what empathy is from someone without aspergers. Certainly, you can listen to how empathy is described, but you can't truly know what it is like to have empathy (according to your reasoning), so you couldn't know whether others had it or not. The most you could ever say is that you personally do not experience feelings like those associated with empathy.
Now, the autistic spectrum certainly describes a difference based on social and emotional characteristics, but I am pretty darn sure that "lack of empathy" is not a requisite for a diagnosis. While an unawareness of social and emotional cues may indicate a social or emotional difference such as the difference described by the autism spectrum, this in no way means people with aspergers or people with any other asd must lack empathy.