Concerning the words in the Scriptures: "And it shall be, if thou shalt forget the Lord thy God..." the Rabbi of Rizhyn said: "It is well known that by every 'and it shall be' in the Scriptures, gladness is meant. Here too, this is what is meant. Here we are told: 'If you forget gladness and fall into a depression, you are forgetting the Lord your God.' For it is written: 'Strength and gladness are in His place.' "
from Martin Buber's Tales of the Hasidim - Later Masters