If you are always losing your keys in the morning or walking out of the house without your mobile phone, sleep deprivation could be to blame.
A study found a lack of sleep makes us feel foggy for a reason, because brain cells lose their ability to communicate with each other – just like they do when we have too much to drink.
Temporary mental lapses are now believed to occur when these cells struggle to translate visual information into conscious thought.
It means if a bunch of keys are in front of someone, they could walk dazedly past without picking them up.
Brain cells, called neurons, were found to fire more weakly and take longer to respond in a study of 12 people kept awake all night.
Neurology professor Dr Itzhak Fried, from the University of California, Los Angeles, who was involved in the study, said: ‘We discovered that starving the body of sleep also robs neurons of the ability to function properly.
‘This paves the way for cognitive lapses in how we perceive and react to the world around us.’
Dr Fried said: ‘Inadequate sleep exerts a similar influence on our brain to drinking too much. Yet no legal or medical standards exist for identifying overtired drivers on the road the same way we target drunk drivers.’
The study is published in the journal Nature Medicine.