The way, I understand it is that with a Poisson process, at every small moment in time there’s a small chance of the event happening. This leads to on average l

The way, I understand it is that with a Poisson process, at every small moment in time there’s a small chance of the event happening. This leads to on average lambda events occurring during every (larger) unit of time. But this process has no “memory” so no matter how much time has passed since the last event, the number of events expected during the next unit of time is still lambda.