Think about your own balance between YinYang being one very long song and dance that lasts your whole life.
During this dance you require times of Yin where we are cooling down, slowing down, accumulating energy and strength for the future, and these times are hauntingly beautiful in their defending energy, and other times the dance requires Yang, fast pace, expression, usage of lots of energy in order to create something of magnitude and of manifestation energy.
Tip too far in either direction, and you’ll pull the curtain sooner on this life long performance. Ignore the dark side of Yin, or the brightness of Yang, and your life will become dull and lacking of vibrancy, as it is the friction and union of both that makes our hearts shine.