The training is a mix of: obsession, up to and beyond exhaustion; grit, driven by passion; a relatively 'fast' metabolism, fueled by food and naps. Nothing magic, bootcamp-style.

Basically, working your day thing (studies, work, obligations) then spending all your free time nerding on something. It progressively morphed from goofing around to learning with a professional mindset, building stuff.

It's important to pace yourself; it's a marathon on a daily basis. However in the long run, over the weeks, it's more like an agile sprint: you work a lot for some weeks or a few months at most, then relax, rinse and repeat.

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The happiness switch

I've found there are fundamental functions in human beings that pretty much describe us entirely. It's a model, deduced from reality, which in turn helps me 'mold' my reality (i.e. aspects of my personality, how I choose to experience things).

This set of skills can be trained; it seems to be 'working' with anyone, but there are 'prerequisites'; exactly which is unclear (for now).

One of the by-products of this is a happiness switch: your emotions inevitably vary, but you are able to maintain your desired "global state" nonetheless. So you do feel sad sometimes, or angry etc.; but at the same time, it's only one aspect of you, one function, namely emotions are the "language of the body", it's just information. They shouldn't drive you, but inform your decisions, your choices. That's one thing you can train. This is where Shakespeare's famous quote takes its full meaning imho: “nothing good or bad but thinking makes it so.”

Emotions are energy though: all our functions produce some 'effect', which may be usable, alone or in combination with others — for instance, cognitively we know that emotions act as a catalyst for memory, to break out of 'RAM' into long-term knowledge. This is a bridge (a powerful one, it's called 'passion' in some cases, 'impression' in other contexts...) between emotions and thinking.

The main sources are Stoicism and/or comparable schools of thought (Zen notably, and a cross-slice of many religions, myths), some critically validated modern 'self-development', cognitive studies (psychology, neurology, etc., e.g. the "hexaco" model), and books/authors/ideas in-between that demonstrate the empirical/statistical 'truth' of some principles (those that endure the test of time, with success). Also a bunch of business/consulting literature that strongly validates ideas, if only empirically — plus autobiographies etc. The spirit of the general enterprise is to validate sources by who speaks — e.g. only take advice from those who succeeded at what you seek, preferably the greatest, including people you don't like — and validate ideas themselves by experience, by real-world application.

So while the endeavor might seem quite intellectual, it's only the tip of the iceberg, the small gate of knowledge — immediately after lies practice, lifelong mantras. That's actual philosophy, what the word meant until the turn of the 20th century: practical advice and repipes for a good living.