My mother-in-law always used to say this and I recently stumbled upon a quote that seems rather fitting so i thought I'd post it:
Who will tell whether one happy moment of love,
or the joy of breathing or walking on a bright
morning smelling the fresh air, is not worth
all the suffering and effort which life implies?
Erich Fromm (American Psychoanalyst)
I have it framed on my kitchen window ledge so she's never far from my thoughts and if I'm feeling a little sorry for myself it always seems to make me smile.