It’s common knowledge that people are likely to feel blue during the winter. The days are shorter, the sun is sparse and you have to wear so many extra layers of clothing anytime you’re feeling brave enough to take on the cold and set foot outside. In recent years, however, the feeling people usually write off as the winter blues has been diagnosed as a medical condition: Seasonal Affective Disorder (SAD). SAD is a kind of depression that occurs in individuals from winter until the weather breaks in the spring. It’s even more common in women and individuals who live farther from the equator (because the days are shorter).

Doctors and other experts aren’t exactly sure what causes SAD, but they think it has to do with the lack of sunlight. Less sunlight may alter your biological clock, which controls plenty of the regulatory systems in your body, like your sleep cycle.

Most individuals who experience SAD show start showing symptoms in September or October and are relieved of those symptoms by April or May, according to WebMD.

When you’re feeling a little blue this winter, these 10 motivational quotes are sure to brighten your mood:

1. “Love is the flower you’ve got to let grow.”
John Lennon

2. “Life is the flower for which love is the honey.”
Victor Hugo

3. “Love is like a beautiful flower which I may not touch, but whose fragrance makes the garden a place of delight just the same.”
Helen Keller

4. “I want it said of me by those who knew me best, that I always plucked the thistle and planted a flower where I thought a flower would grow.”
Abraham Lincoln

5. “When you take a flower in your hand and really look at it, it’s your world for a moment. I want to give that world to someone else. Most people in the city rush around so, they have no time to look at a flower. I want them to see it whether they want to look at it or not.”
Georgia O’Keefe

6. “Autumn is a second spring when every leaf is a flower.”
Albert Camus

7. “People don’t notice whether it’s winter or summer when they’re happy.”
Anton Chekhov

8. “In seed time learn, in harvest teach, in winter enjoy.”
William Blake

9. “O, wind, if winter comes, can spring be far behind?”
Percy Bysshe Shelley

10. “You can’t get too much winter in the winter.”
Robert Frost

John Lennon quote Love Is A Flower You've got To Let It Grow