It takes a considerable amount of skill and focus to keep multiple plates spinning without letting any fall and break.
It's almost ingrained in us to constantly strive for this level of productivity, and we may even feel guilty if we're not "spinning" as many plates as the most successful and busy individuals.
We might even add more plates to our collection just to avoid having idle hands (which are said to be the Devil's workshop).
Before long, we're using all our mental and physical energy just to keep these plates from crashing down, often forgetting why we started spinning them in the first place.