You’re in a room with a fan blowing. It isn’t too noisy. Certainly not noisy enough to prevent you from working.
Or maybe there is some work been done in the street, and you hear the background noise of vehicles, generators and power tools from time to time.
But then, at some point, you turn off the fan, or the street noise stops.
What a difference. It’s only when the noise stops that you realize how it has been filling your head and distracting you. Turn off that background noise, and you feel relief.
The same kind of things happens when you spend your day with a background of constant emails and social media. It’s just a different kind of noise.