Dream and real Life

How does one differentiate dream and real life ?? If one dies while dreaming in sleep, is there any chance for him to know that it wasn't reality, but a mere dream ?? If one wakes up after death, doesn't life look like dream ??
One may answer like this ... Dreams don't have links among them, in the sense, between y'day's dream and today's dream there may not be any relation at all & one won't be knowing the happenings of the earlier dream in today's dream, where as in life that's not the case, as we do remember what has happened y'day ! That means, when two states are related and latter state knowing about the ealier one, then these two are reals and the in between state is dream and vice-versa... If one agrees to this, after death when one wakes up in a new body, there will be neither apparent relation between the states before n after death nor knowledge of earlier life .. So, is life also a dream ?


(Questions raised while reading "Achanchalam", which means steadyness)