As mentioned, I am a fan of The School of Life, their mission, and their products. This book continues that fandom in a strong way. And with this book, I'm well on my way to reading a significantly large number of essays this year.
This is a short book, 96 whole pages divided into six sections: Self-Ignorance, Philosophical Meditation, Emotional Identity, Honesty and Denial, Self-Judgement, Emotional Scepticism. The section that delighted me the most is the Philosophical Mediation section, as it explains the (classical) Stoic process of dealing with the stresses and worries of life by asking (and processing) the questions "What am I anxious about?", "What am I upset about?", and "What am I excited about?".
The last three sections were also particular relevant to me, but, well, your mileage may vary with this book. If you're in a reflective mood, this book is amazing and possibly a life-changer. That life-changing assumes the reader processes the book, and doesn't just read it, shrug, and toss it aside.
Normally, I'd list all the quotes of the book I found meaningful. Here, however, I realize that the parts I find relevant are revealing in a way I find too vulnerable. So instead, here's one note from the Faulty Walnut:
The walnut is extremely bad at understanding why it is having certain thoughts and ideas.
It doesn’t typically notice the role that levels of sleep, sugar, hormones and other physiological factors play upon the formation of ideas. The walnut adheres to an intellectual interpretation of plans and positions that are, at base, frequently merely physiological. Therefore, it can feel certain that the right answer is to divorce or leave the job rather than go back to bed or eat something to raise blood sugar levels.
If you're in a place where you're ready to reflect internally and grow, this book is amazing, let me buy you a copy.