Disambiguation ,i.e, separation of "one" from the "other" , is the basic unit of thought
....and thinking thus yields a disambiguated picture of what is the mind independent objective reality that we intake through our sensory perceptions and that’s where the problem starts. Reality "in itself" is an integrated whole, it is a cognitive limitation of our thought process to see it in terms of constituents. So thinking has to be balanced by "feeling", that is to say, one has to think life and live life at the same time. Thinking independent of living and living independent of thinking is the same, both useless. Yet again to be "useless" or "useful" in life... one has to define a "use" first, now that’s a fundamental problem.
Most of us define it narrowly in the manner that we our conditioned by our environment through numerous reinforcements (both positive for certain things and negative for certain others). If one tries to break away from the context of his life, only then one makes some sense of life which is absolute, but in the context that our life inherits, this sense of realization may transform from being absolute to being absolutely "useless". Perhaps the need to take care of the context of one's life (parents, society, money, country, culture, systems etc) as a hygiene factor, i.e., something which needs to be done in order to be "not sad". Then, once one reconciles the context to one’s envisioned absolute purpose (self-actualization maybe??) by say earning enough money, having enough sex, having enough of an ego trip etc, so as to be able to move to a higher level of existence without the contextual needs bothering you, only then can one aim at being "happy". I suspect most people in life, by chasing grades, sex , money, ego etc are just trying very hard to be "not sad" under the illusion of chasing happiness. From their lives, “happiness” is missing. While on the other extreme there is a minority chasing "happiness" by focusing on the sublime and the transcendental and disregarding grades, sex , money, ego etc wishing all the time that they be "not sad" , but of course that never happens. From thier lives "not being sad" is missing. One needs to be both "not sad" and "happy" to feel free of the dread of existing meaninglessly. A need is a felt sense of deprivation. A sense of deprivation felt most often and most precisely can be characterized as a basic need, like food, clothing, shelter and in the modern society add communication/transportation...and go on in that order. One feels deprived of food every few hours and one knows what one has to do to relieve that need - one has to eat.
A sense of deprivation felt less often and more profoundly is a perhaps a higher order need. E.g. one often feels an indefinable anxiety, one does not even feel it in discreet units, it is almost like a leitmotif of life, like a background noise out of your control rendering everything less of meaning and satisfaction. One does not even have the wherewithal to define it. And that’s when you don’t even know what the hell to do about it. Now the fact is, in reality, unlike Maslow would have you believe, these needs don’t come in serial order, all the needs our present all the time, we just miss some and focus more on others. One has to keep everything in mind. The clarity one achieves along the course of life of the sense of deprivation one has is what dictates the action one takes to mitigate that deprivation.
So, I guess, the best one can do is, to at least undo all the sense of deprivation one clearly feels and knows what to do in order to be free from it, and it’s my belief that by doing so this arrangement of different deprivations will become clearer in a stepwise fashion, like ice melting off layer by layer, and revealing a deeper truth every time