mrpink essays

Shamanic Teachings for Personal Leadership

A 7-day fast, Castaneda, and willpower as a transformative force

Many years ago, I read The Teachings of Don Juan by Carlos Castaneda. Castaneda, a young anthropology student at UCLA, ventured into the Mexican desert to study shamanic practices and was fortunate enough to be accepted as an apprentice by Don Juan, an older shaman.

In that book, Don Juan explains that the path to becoming a “man of knowledge” is filled with enemies:

Fear → paralyzes and prevents us from acting.
‍Clarity → gives lucidity, but can turn against us if we believe we know everything.
‍Power → can intoxicate us, isolate us, and lead to empty ambitions.
‍Old age → an inevitable enemy, at least for now.

It’s a learning framework that, although narrated in a shamanic context in 1960s Mexico, resonates surprisingly well with today’s entrepreneurial journey.

Without overcoming fear, it’s impossible to take the risks required to start a company.Clarity, if it turns into arrogance, makes us stop listening.Power can disconnect us from others and make us ruthless.Only the development of willpower allows us to move through these stages without losing ourselves along the way.

Preparation

Before going further, let me clarify: this text is not medical advice. If someone wants to experiment with extended fasting, the best path is self-knowledge and consulting professionals.

In my case, I came prepared: years of practice and detailed research that included a solid supplementation plan. The key is to keep electrolytes stable: sodium, potassium, and magnesium. For extra peace of mind, I added multivitamins, though not strictly necessary for a 5–7 day fast.

The fast

I decided to start the fast on a Wednesday night, after dinner with my family. That also closed my strength training cycle. From there, a different kind of week began.

Days 1–2: the start and the shock

Day 1 passed without major issues. I went to the gym, finished my training cycle, and cooked for my kids as usual. No difficulty.

Day 2 was different. Soon I felt intense thirst and a constant dry mouth. I started urinating a lot, and by nighttime I felt tired. Cooking and sitting with my kids at dinner wasn’t hard, but sleeping was: I woke up several times to pee and had cramps. Later I understood it was due to low sodium. A clear lesson: salt is fundamental to prevent dehydration and keep the body in balance.

Days 3–4: adjustments and clarity

Day 3 began with fatigue after a bad night’s sleep. I doubted I could reach my goal. I increased sodium intake and stabilized. That night I slept better. I still woke up several times—normal in long fasts—but it wasn’t a problem.

Day 4 I woke up with unexpected calm. A sharp mental clarity, a hard-to-describe peace. Even meditation felt deeper. But in the afternoon, persistent abdominal pain appeared: the so-called “physiological hunger” that often arises between days 3 and 5. I didn’t have a true desire to eat, but the body was sending signals. I endured. I leaned on melatonin to sleep better that night, and it worked.

Day 5: energy and paradox

Simply surprising. I felt light and mentally sharp throughout the day. At the office, it was one of my most productive days in a long time: I finished an investor report, cleared pending tasks, did deep analysis, and made several important decisions with ease.

But the night was challenging. Despite melatonin, I slept very lightly, woke up often, and felt a persistent abdominal discomfort, almost like an inner vibration. The paradox of the process: while the day was filled with energy and focus, the night revealed the body’s fragility in transition.

Day 6: normality and calm

The day went smoothly. Instead of walking on the treadmill, I started the morning doing yoga with my wife and then went to the office. I felt good all day: clear mind, body without discomfort.

At night, I went to bed more relaxed, knowing it was the last night of the fast. That certainty reduced the anxiety of previous days. I woke up around 4:45 a.m., which isn’t “that” early for me, since I usually get up at 6 to meditate. When I opened my eyes, I thought it was later: I felt instantly awake, without the grogginess that so often comes with waking.

Day 7: closing the process

The day felt similar to the previous one. Surprisingly, I didn’t feel hungry at any point during the fast. Only on day 4 did physiological hunger appear, along with occasional unpleasant stomach sensations, but never too intense or lasting.

The key was detaching from old habits and accepting that, as long as I decided the fast continued, I wasn’t going to eat. And doing it without suffering—because it was my will to do so.

What I missed most wasn’t the food itself, but the social activity of sitting at the table with my family and sharing that moment. I replaced it with the pleasure of cooking for them and enjoying watching them savor the meal.

The body in transition

During the fast I maintained daily physical activity: 40 minutes of treadmill walking, staying around 114 BPM, the fat-burning zone. As the days went by, I noticed I reached that heart rate at lower speed and incline. Researching, I understood why.

The body has three sources of energy:

It shifts from glycogen to ketones, and eventually stabilizes around 20% ketones, relying almost entirely on free fatty acids as its main energy source.

Conviction and Will

The most surprising thing was that I never felt strong cravings to eat. There was no mental struggle against hunger. The key was starting with a very clear conviction: I knew what I wanted, understood how my body worked, and trusted that I would be fine.

In the PinkLetter The DEQ Matrix and Cold Water I talk about the importance of aligning action with a defined purpose. Here it becomes evident: when what I want is clear, willpower isn’t wasted on resisting, but on sustaining. That certainty calms the mind and creates space for clarity.

And there Castaneda returns: willpower as power. Not just endurance, but a deep knowing—not mystical, but practical—that one can sustain what one has decided.

Fasting, as a liminal practice, placed me on a threshold: not in the ordinary nor in the extraordinary, not fully weak nor fully strong, but in transition. And on that threshold, the most powerful sorcery is revealed: the one each of us exerts upon ourselves, when we allow willpower to be fully present.

Clarity

On the path Don Juan describes, after fear comes clarity. A clarity that can be dangerous, because it makes us feel invincible, too sure of ourselves. But it’s also a fertile state: it allows us to see with sharpness what previously seemed blurry.

During this fast I experienced something similar. Hunger faded into background noise and, in its place, an unexpected lucidity emerged. A lighter, less scattered mind. That clarity, in the context of fasting, feels like inhabiting a liminal space: a threshold between the physical and the mental, between fatigue and energy, between the impulse to eat and the conscious decision not to.

On that threshold, transformations happen almost on their own. The body learns to use other sources of energy, and the mind discovers it can sustain itself without constant immediate gratification. It’s a reminder that transitional states—the uncomfortable ones, the disorienting ones—are also the ones that open the door to transformation.

Closing

I take many lessons with me. This experience deepened my understanding of how the body works and the role food plays. I feel fortunate to be able to engage in such a practice by choice, while at the same time having access to abundant, healthy food.

I now understand more clearly how body and mind function—which, from my non-dualistic perspective, are one and the same. The mental clarity that appeared from day two stayed with me until the end.

My self-confidence grew as I confirmed that I can reach challenging goals if I have the conviction to sustain them and the clarity to execute them. And what’s valuable is that these lessons are not limited to food: they can be extrapolated to personal growth, professional life, and—of course—to startup leadership.