Hm... Yes, I think that understanding the emotion is important as well as admitting. Many people just won't admit certain emotions. How many times have we heard phrases like "I am not jealous" or "I am not angry, I AM CALM" or similar. I would still say it has more to do with denial than lack of understanding. Emotions are something too basic to not be understood properly. Although I personally can relate to both scenarios. e.g. As I really had pretty much no tendency of jealousy, I didn't really know what it feels like until I was over 20-something. I remember at one point that I had this "weird emotion", because of something (I think I was 20 or 21) and this is the first time I realized it was jealousy. I may have had that emotion just a few times in my life so I wasn't familiar with it. But it was just too simple to not understand it so I don't believe that a lack of understanding is that much of a problem.
Also, there are many emotions which are actually the same, only their association is different. e.g. The emotions of fear, excitement and desire trigger actually identical sensations in the body (if I remember right, even the same chemicals), only their association (in form of images, sounds, smells, kinaestethics, etc.) differs. A neutral association would cause desire, a negative one fear and a positive one excitement. Once I was made aware of that fact, I've tried it out many times and I realized that they really are the same emotion. You can imagine how my mind was blown. >.<