The Previous Rebbe once related to one of his chassidim: It is told about one of the spiritual giants of years gone by that on his cane was engraved the letters gimmel, zayin, and yud, an acronym for the words "Gam zeh yaavor - This too will pass."

When one's fortune turns against him, one should not become downtrodden. Rather he should recognize that all things come from G-d, and further, that this too will pass.

Otzar Pisgamei Chabad, p. 174