I moved next to an airport. Every morning at 6AM I'd get woken up by jet engines at full power taking off. One day I realized that I was no longer waking up at

I moved next to an airport. Every morning at 6AM I'd get woken up by jet engines at full power taking off. One day I realized that I was no longer waking up at 6AM. Either none of the 6AM flights were running anymore or I just no longer heard the noise. And of course, the flights were still running.