it is a memory or a vision but most of the time it is an illusion
Usually you dream. You're brain is more active when it's asleep than it ever is when you're awake.
Testicles do not fall asleep.
Even when your asleep your brain is still at work. When we fall asleep we go through different stages. Some scientist think that when you fall asleep the brain sorts information it has been receiving during the day. Some information gets rid of and some gets filled in your memories. :)
S(he) is dreaming . . . no doubt about chasing cats and rabbits. His brain sends tiny signals to the legs to run. Humans also have similar behavior, but because we are asleep when it happens, we never know it.
it is most active when your asleep because it goes over what you did, learned, and saw.
False
is it a metaphor or ..
Not necessarily. The brain is constantly working regardless of whether you're awake or asleep. Some areas, however, will be more active when sleep and some when you're awake.
Because you are sleeping
when you have nightmares it is just the brain playing tricks on you perhaps off something you thought off before you fell asleep
he falls asleep
They relax normally.