Spirituality and practices
Trekking in Himalayas only for the sake of posting cool pictures on Facebook is, of course, wasting of time and money, unless one uses it as a catalyst for inner transformations, to practice austerities, reasonable asceticism and, most importantly - to develop a new habit of always being here and now - to tame one's aimlessly wandering mind and uncontrolled senses.
In trek I am trying to [reverse-]engineer and transform my own flawed models of the world, based on false "memes" (naive social constructs) and flawed mental concepts, imposed on us by shared social environment (nationality, tradition and religion, culture, social class) and then permanently alter my habits (conditioning), which is the only "working" way to a profound and everlasting personal transformations.
My current knowledge is merely a synthesis of a few insights of ancient schools of thought, such as Upanishads (and some parts of Advaita Vedanta) and the Buddha's own teaching (Dharma), together with some facts from modern evolutionary psychology (which is based on findings of the cognitive neuroscience) and best-researched models and algorithms from the filed of Artificial Intelligence.
With this knowledge I could concentrate upon these very few brilliant insights and efficient practices of ancient Oriental philosophers which nowadays are buried so deeply under piles upon piles of graphomanic or narcissistic or mere commercial nonsense that mediocre people wrote for thousands of years.
Here I am not emphasizing the personalities of teachers, but rather focusing on their realizations and deep insights. Most clarifications were given by explaining "what it is not" (like the Yoga, described in the Sutra of Patanjali, is not an equivalent of Western "physical culture" and it is not about "asanas", which is a later addition of "street gurus" of lower castes - a social construct).
This notion of "ruining" of a subtle teaching by later additions and extensive commentaries is such a common pattern, that we would see it everywhere. The most striking example is return of some Tibetan sects back to idol worshiping (of guru Padmasambava and other deities) and even transforming of the Buddha into another idol, which is a direct contradiction to the teaching of "mental austerity and direct insights".
Know thyself. Conquer yourself.
These are the oldest and greatest maxims of all time. Basically, one should spent his time to these two tasks - get to know oneself and then develop a new set of habits to gain better control over what he is.
I have done this unintentionally in my youth. I suffered a lot from bulling and hatred of my classmates and other people around me. No one told me then that I have so-called Asperger Syndrome and I have understood the causes of my suffering only much later. The small set of ideas I have developed to pull myself out of that misery, it turns out, are mimicking ancient spiritual practices for the East. I call it 100% idle as a description of the state of the mind (and body) which one should develop via habituation to be able to undo and unlearn wrong habits, based on unfortunate personal experiences and social conditioning.