Why you'll forget why you invested

Here's an experiment you can run on yourself. Pick an investment you made three years ago and write down, from memory, why you did it. The actual reasoning at the time. Not the story as it stands today.

Now go find anything you wrote back then. An email to a partner, a note in the deal folder, the text you sent your spouse.

If you're like most investors, the two don't match. And the direction of the mismatch is predictable: your remembered reasoning has quietly drifted toward whatever makes today's outcome make sense. The winner was "obvious conviction about the team." The loser was "a small flyer I always had doubts about." Neither of those was quite true on the day you wired.

Psychologists call it hindsight bias, and knowing the name doesn't protect you from it. Memory isn't a recording. It's a story that gets re-edited every time you tell it, and the editor's job is to make you look consistent.

Why this actually costs money

This would be harmless vanity except that your past reasoning is an input to real decisions.

The follow-on is the obvious one. The company raises again, and the question is whether to defend your position. The single most useful piece of information is what you believed at the start and whether it's still true. If the thesis was "this founder will figure out distribution" and two years in she has, that's a signal. If your memory has already rewritten the thesis to match the current story, you're deciding with corrupted data.

The other cost is slower: you can't learn from decisions you can't accurately recall. A track record isn't just outcomes. It's outcomes matched against reasoning. Without the reasoning, wins teach you that you're smart and losses teach you that you were unlucky, and neither is learning.

The ten-second fix

Write down why, the day you invest. Before the outcome exists. One honest line is enough. "Betting the founder can sell into hospitals, would exit if she can't land two systems by next year." That's a thesis, sell trigger included, in one sentence.

The rules that make it work: write it before you wire, not after. Include what would make you get out, because that's the part you'll rewrite most aggressively. And put it somewhere you'll actually find in three years, which disqualifies the group chat.

If you invest with partners, have each person write their own line. The disagreements you surface at that moment are worth more than any consensus paragraph written afterward.

That habit costs nothing and works on paper. It's also the habit our product is built around, a thesis captured at decision time, attached to the deal, searchable years later next to what actually happened. The investment memo template is a free place to start, with or without us.

The only version of your reasoning you can trust is the one written by the person who didn't know how it ends.