This explains a lot

Be less lazy!

Lazy is evolutionary, to keep us from doing stupid things when we might need the energy to run away from danger or find food or water or shelter.

Busy is apparently the mind's way of looking for something to do that will increase utility (happiness). Downtime needs to be filled with something or boredom from laziness sets in as a mood in and of itself. Since modern societies leave little need for finding bare necessities of survival, it's pretty much GIVE ME AN ACTIVITY! being screamed by the brain.

I'm sure that goes over well when it involves other people.