Here's the simplest definition of optionality: Optionality = the right, but not the obligation, to take action

Every tiny facet of the world is so ridiculously fascinating that you’d have to be deaf, dumb, and blind not to notice. If you want to be interesting, be interested. Lack of intrinsic interest is a big red flag for learning any skill.

A successful business or career pathway usually emerges organically from the bottom-up, instead of being planned from the top-down. This approach benefits from volatility. It doesn’t rely on complex multi-decade plans full of contingencies and breakage points and prediction errors. It looks a lot more like Darwinian evolution than intelligent

To illustrate what I mean, here’s the strategy I use for my own portfolio. For reasons that will become clear, I call it the ‘Bastard’s Barbell’. This is a split between low-cost index funds on one side, and risky speculative bets on the other (Fig. 4.3).

To carry a debt is to be ‘owned’ by someone—or by multiple someones. Your creditor has the right to collect, or otherwise make your life difficult; you have an obligation to make repayments. In servicing the loan, you have to earn an income somehow. Now you have two owners: your creditor, and your employer.

Leverage gives you exposure to major upside, but it's not an asymmetric opportunity. If the market falls, any losses you make are also multiplied several times over. If property prices fall by 20 per cent, in our scenario above you’re down $100,000, which means your deposit has been completely wiped out.

According to Aristotle, our reason for existence is to be happy, in the fullest sense of the word—what the Greeks called eudaimonia. Hedonic pleasure is not enough to reach a state of flourishing: we must also live a life of virtue, and use all of our capabilities to their fullest. To live without virtue is to fail to reach our true purpose—like a

3. Knowledge Capital All your skills, education, credentials, and experience—work, or otherwise. 4. Health Capital Your physical fitness, mental health, mobility, and energy. Remember the kind of asymmetries we're looking for. An attractive option has a fixed downside, and potentially unlimited upside.

The economist Frank Knight formalised the distinction between risk and uncertainty in his PhD thesis more than 100 years ago, with the key difference being that risk can be quantified and measured, while true uncertainty cannot.