I guess if we want to make jealousy and envy exclusive from each other, then in terms of having something being taking away, it would have to be in relation to someone I may be in a relationship with (e.g. camaraderie with someone, significant other, etc.) If it’s just a conceptual thing – something abstract, then I can’t really feel insecure or threatened if certain competencies are taken away as this isn’t something people have direct, third-person access to that individual’s subjectivity. In other words, people can't take out bits of your cognition until you're equivalent to someone going through a lobotomy. That’s because it would be their, that individual alone's, own doing where they start doubting if there can be a long-term continuity of their own intellect, and well-being.
Now, when it comes to others, I can understand how this could be applied where someone has to compensate in not being able to exhibit a type of continuity they’re used to for the sake of conformity, and rapport with another person. But, I think that’s a two-way thing, and if it becomes one-way, then again, the person in question is the one that set themselves up for having something lost or taken away from them.
As for applying jealously towards competencies a person doesn’t have, then I can’t really extend my feelings towards that as ‘envy’ since that has a substantial incentive towards chalking up those insecurities I may have. But, for the sake of getting it out there, I guess, instead of developing some kind of inferiority complex wondering why you can’t overcome this lack of something you don’t have; even types of intellect you wish that if added, you could have a greater continuity of your well-being, I like to think of an analogy of interpersonal interactions with others:
In a way, metaphorically speaking, we have to project a little bit of ourselves with others. It’s a means to develop rapport, or to establish some negation with another person. People project a little of themselves towards us as well. Instead of feeling intimidated, or realizing there some aspect of them that seems to fit the missing piece of what your intellect and competencies may be, let a little of themselves bleed onto your own continuity of self. Be inspired by it, but at the same time, don’t put that person on a pedestal for very long because everyone slips up, and if you let your inspiration of them be dictated by their shortcomings, you’ll always be disappointed in them.
But instead of being disappointed by them to make yourself feel better, just be self-aware that in spite of that repertoire of aspects they have that you wish you had, or you wish could finally solve that missing piece in your well-being, take ownership of that inspiration for self-progression, and not trying to worry about their own self-progression to distract yourself in taking ownership. That way, no one fabricates a scapegoat just because they lack something, especially when it’s something they could learn with experiential context developed over time.
TL;DR: I guess this is how I would assess jealousy, and little bit of envy as well (since I think they’re correlated depending on the context). They’re transient feelings, and also a chance to reign in your sense of sense and realize, ‘yes, I feel there’s something about them that I feel would fill the void of whatever intellect I may have, but maybe, if I keep experiencing and learning, I could learn what it means to have that aspect of them.’ Unfortunately, this would create the implication of me over-simplifying that certain things can be attainable over time, but I’m well aware that certain limits (genetics, physicality, etc.) can make things difficult to obtain. But, that doesn’t mean our minds can't be spurred to find potentially new, novel experiences to compensate, and find a loophole around to reach a similar outcome.
In other words, I focus more on unconditional, positive reinforcement if there’s something I desire that I see from another person. But, I don’t feel my intellect or continuity of self is threatened; it’s just an opportunity to own up to my insecurities, and continually experience to build self-progression.
