Simply thinking that you've had a good night's sleep is better for your mood than actually having one.
Thinking you have slept well can boost your mood
New research has found that instead of paying attention to how much shuteye they get, simply feeling as if you have rested well has a more significant impact on mindset.
A team of experts from the University of Warwick asked more than 100 people aged from 18 to 22 to keep a daily diary about how they had slept the previous night.
This recorded details about what time they went to bed, how long it took them to go to sleep and how happy they were with their slumber.
Participants also wore an actigraph - which measures a person's movement - on their wrists to estimate sleep patterns and rest cycles.
The results revealed that those who felt that they had slept well were in a better mood the next day.
Lead author Dr. Anita Lennis said: "Even though a sleep tracking device might say that you slept poorly last night, your own perception of your sleep quality may be quite positive.
"And if you think you slept well, it may help better your mood the next day."