Understanding the Archetypes involving the eight functions of type (Beebe model)
Sorry guys if by just reading the description of the process of that shadow function you actually started to see certain horrifying images which reminded you of that special episode in your childhood which might have scarred you for life. But if this indeed happened it should be good news for you, because it meant you really are an ENTP instead of some ENTP wannabe.
Back in college there were a few occasions where I suddenly became furious towards my roommates and threatened them with all kind of evil things just because they said certain words or behaved in a certain way which made me feel like I was reliving my crazy memories again. Every time I would feel bad and apologize to them afterwards, but what I was never able to figure out was why I was so easily provoked by some small and insignificant stuff.
Se is actually a very powerful function which can in a large measure determine who you are and the path you take later in life. The only way to own it, according to Jung, is to fully experience the emotions associated with the bad memories. Ignore it or, more stupidly, suppress it is the best way to ensure those painful experiences will haunt you for life.
Jung also said Ne feels just like Se, both of them are a process of establishing relations with objects by sensation. The only difference is Se pays close attention while Ne mainly looks for patterns. Ne users like ENTP or ENFP can get a glimpse into the lives of Se users like ESTP or ESFP (natural masters of living in the now) by remembering your bad experiences from the past (painful exercise not for the feeble of heart). You can see how you can recall every little detail as if you are watching a HD movie inside your mind. When you try to remember you happy memories the images or movies tend not to be so clear and you usually can't remember the whole process.
My guess is some ENTPs appear shy and reserved in many situations because of the hidden force of Se, whose energy remained unreleased. When the energy is released the problem will naturally disappear.
Another possibility is Ti takes on too big of a role. Ti concerns logic and sometimes can't understand the awesomeness of Ne. This function is what makes a lot of ENTPs look like INTP. But you are not an INTP if you don't have a tendency to show disrespect for feeling.