Moderation

Why Daoism emphsis "moderation"? The ultimate goal "nothingness" does have nothing. Sad, hapiness, angry, love, most human things. Then how can you live in current society? This is why monks live in the mountain in Tibet. If somebody emphasis he/she is spiritual all the time in this society, s/he'd better to go to mountain and live alone till get soul body. Moderation makes you keep spiritual and makes you can live in human society.