Hey Prince
Well if you'd ask me emotions are never stupid. One doesn't decide to have them and one can't switch them off. It's best to think of them as something which your mind produces to convey a message to you. I often have feelings and intuitively understand them, but I can't quite put them into words. If I wouldn't have a feeling accompagnying them, I probably would never start to think about these things in my mind I can't put into words.
I'll admit it, I often feel jealous, compassionately so even.
Feeling jealous has two components: One is subjectively feeling that another person does not deserve what they have or that at least oneself deserves as much what the other person has, and the other aspect of jealousy I think is that in some way it is a form of high appreciation. That is, to be jealous of someone else's attributes, be it their abilities or something material they have, means you estimate the worth of what they have very high. I think this is also the reason why people with low self esteem may feel jealous of others more often.
The last thing which comes to mind, I think jealousy is a feeling we often aren't aware of. Some people would say they never feel jealous when you ask them, but I genuinely believe this is rather due to not being aware of it when they actually do feel like that.