As u/usernameblankface said, 8 minutes is the time it cooks while fully pressurized. It can take anywhere from a little over 5 minutes to a half hour or more to heat up everything inside enough to generate the steam necessary to pressurize.

Aeropress coffee was always the best tasting. But I found I just didn’t have the patience for making it that way every morning, especially since I drink four cups at least.