Mono - That is so true.
I have been in that situation before - not understanding how someone could be jealous when they were feeling so.
How do you think that gap in understanding could be bridged? Would you (not you specifically) want someone to feel jealousy in order to understand the emotion?
And - I take back that I have never felt it. That isn't true. It is more like it is an emotional response that I always manage to talk myself out of fairly quickly. So, it is more of a misunderstanding of why the jealous feelings persist, not that they come up at all.