Dreams

why do we have dreams and
how did dreams came to our brain ?

The measurement of brain waves have shown through research that sleep
is not all the same. A night sleep seems to have a series of regular
cycles. One of these stages is called Dream Sleep or Rapid Eye
Movement sleep because your eyes move rapidly behind your eyelids
during this phase. It is thus labeled REM sleep. REM sleep is not
really light sleep or deep sleep, but is characterized by faster
breathing and heart rate than other stages of sleep. The brain has
increased blood flow and uses more oxygen during REM sleep. This may
explain why people awaken during REM sleep often have vivid memories
of dreams. The first REM period occurs about 1-2 hours after falling
asleep and is the longest of the 4-5 REM periods in a normal night's
sleep. They occur once every 90 minutes or so.

The key aspect to address your question is that the brain is very active
during REM sleep and may explain the dream phenomenon.

Sorry so long.
I hope this helps.

a dream is kind of like a pile of things that you did earlyer that day, or maybe even the day before. your mind is taking things from that pile, in no preticular order, and adding there own something else to the memory. then, you see it, because your mind chooses to see it.
Ex.
You got bullied by two kids you thing smell like diapers
Your brain might see it in a dream as:
Two diaper people chasing you and trying to put a diaper on you.

LOL!!!
hope this helps!

haha...good one ! thx ! but I still don understand why it can come, we can think about it...etc. but thx !