And if you're driving to the office, that's 450 hours where you can get into a fatal accident, with about half of them in the morning when you might be too sleep-deprived to safely operate a motor vehicle. Driving on four hours of sleep is the equivalent of drunk driving. And if your start time is the same every day, then it's likely you'll have many nights where you fall asleep too late, maybe even because you're preparing a presentation for your morning meeting...

Or 450 hours of breathing with polluted air stuck in an outdated underground train system - https://www.cam.ac.uk/stories/london-underground-pollution