This was my final internship. I had had 2 previous experiences on the sell side where I understood it wasn’t what I wanted to do. I wanted to be on the other side, take the long view, and build something that “compounds”.

I had joined an asset manager where I worked along one of the analyst-PM. From the beginning he’d ask me all sorts of things and I’d answer as fast as I could. I never wanted him to think I didn’t know something. So I gave answers to questions I hadn’t really thought about, or I didn’t really know about. Quantity, not quality. Here was the trouble.

I happened to give answers that were more opinions than facts, and sometimes I gave facts from memory that were incorrect. He quickly spotted that flaw and made me realize I had to correct it, otherwise I’d just be unreliable, I could give answers that would jeopardize a whole reasoning. Think about that as building a wall: if your foundations are weak, at one point, the wall collapses. Here’s what he told me : when you don’t know, just say you don’t know. Easy I thought… but changing a bad habit is never that quick.

The more you say “I don’t know” – the more you admit it -, the more you realize the extent of your ignorance. Facing that, you have two choices 1/ run away from it because you’re scared of all the amount you ignore, or 2/ embrace that ignorance and climb the wall of knowledge step by step. So in fact, the more you say it, the more you learn because you put yourself in a position where you’re ready to learn. This is what I did, I gave myself no choice and relentlessly questioned my thoughts and what I took for granted.

Doing so made me realize how little I knew in fact. It led me to ask myself more questions and as a consequence better questions. So I looked at more things and understood better. Saying “I don’t know” led me to turn more rocks so I learnt more. And that’s the power of saying “I don’t know”: you’re aware there are holes in your pictures so you aim at filling them.

Helping me to think probabilistically was the second consequence. When you hold a firm view based on a knowledge you hold for true, you tend to envision a unique future because of the certainty of your reasoning. When you start to say “Ok I don’t know exactly what will happen, I cannot fill these holes, so here are the different scenarios” you envision multiple futures that may pan out. Doing so, you’ll be able to better position yourself in various situations, be it in the investment world (position sizing for instance) or personally (habit building for instance).

Today I can certainly tell that I know and understand more things than when I was 24. But I also expand the domain of what I don’t know. The more you know, the more you understand how much you don’t know. Your knowledge is a circle, the more you know the greater the circle, so the greater the perimeter i.e. your awareness of what you don’t know. It’s a never ending process I enjoy a lot.

It took me 24 years to learn that, talk about a fast learner !