Do you jump out of bed every morning with a spring in your step?
Or is it your partner who is first with a seize the day mentality that you just can't stand?
Well, research now suggests that when it comes to waking up on the wrong side of the bed, it is all about which side you have slept on.
A study by sleep experts at Sealy UK found that those who kip on the right-hand side of the mattress are far more pessimistic than those who doze on the left.
They are also more likely to hate work, which adds to an increase in grumpiness every morning.