If you're suffering from the 'back to work blues' and are even a bit grumpy about it - then we have good news for you!
According to a recent study, grumpy people are more likely to earn more money, live longer and even enjoy a healthier marriage.
"Negative moods indicate we're in a new and challenging situation and call for a more attentive, detailed and observant thinking style." the study said.
"People who are feeling slightly down pay better attention to external social norms and expectations, and so they act in a fairer and just way towards others.
"Happiness functions like a shorthand signal that we're safe and it's not necessary to pay too much attention to the environment."
The same study added that when people are happy and content they become relaxed which can lead to some complications...
"People feel accomplished, they relax, and they do not invest the necessary effort to actually realise these positive fantasies and daydreams,"
"People say 'dream it and you will get it' - but that's problematic," they added.
So next time someone calls you out for being a bit grumpy - at least there might be an upside!