Why do we forget our dreams after waking up?

Isn’t it frustrating to recall dreams vaguely, in bits and pieces, and struggle to weave them back together? If you’ve often wondered why we forget our dreams once we’re awake, here are some possible explanations.

Mostly, dreams tend to occur during the rapid eye movement (REM) cycle of sleep. Experts say that while most of us have between four to six dreams every night, we forget most of them, but are likely to remember the one we experience immediately before waking up.

REM-sleep occurs at several intervals throughout the night, but lasts longer towards the morning. Hence, it is common to wake up in the morning out of this longer phase of REM-sleep, which might explain why we are more likely to remember the dream we woke up from. Prior to recovering consciousness, if there is a transition from REM-sleep to any another state of sleep, the dreams are often forgotten.

Research shows that people who experience deeper, heavier sleep with fewer interruptions, are less likely to remember their dreams compared to those, who tend to wake up frequently — perhaps, during one of the REM-phases. The better and deeper you sleep, the lesser you remember.

Research also suggests that the hippocampus, which is critical for moving information from short-term memory into long-term memory, is one of the last regions of the brain to go to sleep after we have fallen asleep, and could very well be the last to wake up, “So, you could have this window where you wake up with a dream in your short-term memory, but since the hippocampus is not fully awake yet, your brain is not able to keep that memory,”.