Theory of empathy

This may sound completely idiotic, completely obvious, completely redundant, or all three, but reading people's responses to the post on using babies to teach empathy, I thought maybe for the first time I have a theory about what empathy is:

• Empathy is you feeling an emotion you have previously experienced in response to seeing someone else experience something that looks similar enough to remind you viscerally and poignantly of your own experience.  In a way, you are re-living the previous experience, not necessarily feeling what the other person is feeling.  
• Empathy requires some degree of attention to the emotional cues of others to trigger your recollection of your own experience.  
• People who are particularly observant of or in tune with the emotions of others and people who have had a greater breadth and depth of emotions are more likely to feel empathy. 
• To the extent that sociopaths seem to lack empathy, it may be attributed to the fact that they are both (1) relatively oblivious to social cues and that (2) they have a different emotional palette that is triggered less frequently by the emotions of neurotypicals.  
• Sociopaths do have infrequent feelings of empathy when the stars align and the sociopath is both paying attention to the cue and has previously experienced the emotion himself.  

Thoughts?  It's primarily based on Newman's work with sociopath emotions and attentional issues, but I wonder if I am misunderstanding what empaths (or sociopaths) feel.