You’ve been working for years on something. By now you are pretty sure you have it all figured out.
And then one day you have a random conversation with somebody. Suddenly you realize that all this time you’ve had it wrong.
It’s not that there was anything wrong with what you were doing.
Rather, you come to see that what people need is different from what you thought they needed.
The person you’re talking with doesn’t have the faintest idea how to make what you’ve been working on. They just know what they need, and they know how to articulate that need.
And you are reminded all over again that invention does not thrive in a vacuum. Invention needs customers.