Dream Of The Dead

Last night, i had around 14 hours of sleep!
Perhaps its because i was tired after many days of insufficient sleep.
Feeling somnolent during all those bus trips, not getting enough rest.

During the 14 hours of sleep,
i dreamt of my dad who have passed away around 10 years ago,
it seem so real, my family and i was in my old house in Tampines.
There we were all waiting for my dad to come back from a trip from overseas,
when he came back i felt so distance from his being,
it seems like i am close to him but yet i am not,
the memories of my father is fading,
its kind of sad.

Is there any science to the predictability of dream?
Because yesterday's dream was just too random.