Generally, we shouldn't ignore our emotions, but we also shouldn't act on them without reflection. Emotions are signals, sometimes unreliable, but they correlate with something.
This may be a selective memory bias, but my experience is that when I was jealous, there usually was a reason.
(However, I don't want to generalize from one mind. Maybe I am better calibrated than average. Maybe I only receive exceptionally strong signals, where the probability of some real cause is much bigger. There were situations where jealousy didn't warn me. Someone else might be more sensitive to weaker signals, and therefore also have more false alarms.)
Sometimes our minds suddenly "click" and we see a topic in a new light. Or sometimes we think we understand an idea, think it's stupid and ignore attempts to explain it ("yeah, I already know that"), until we suddenly realize that our understanding was wrong.
This kind of insight is supposedly hard to transmit, but it might be worth a try!
So, what kind of important and valuable insights do you wish you had earlier? Could you try to explain briefly what led to the insight, in a way that might help others get it?