Realisation And Knowledge

Whats the difference when you know something and
when you realize something?

Like you know something is significant and something is not, but knowing is totally different than the actual realization of that knowledge. I wonder what really happens when we comprehend the truth behind words and situations? what change takes place in our consciousness, what kind of shift happens that the knowledge becomes real and not anymore just knowledge which we might forget or remember.

Often times in the scriptures, this life we live is compared to a dream. While in dream we believe it to be true and not for a second we have an idea that there is a waker who is asleep at this moment and conceiving the dream. Also the time-space scale changes in the dream. We could dream of years in a short span of few hours of sleep in one night, travel different places, live different stages and moments in life. Similarly the general waking consciousness is also like a dream though a very persistent and strong one, shared by millions. But while in dream its difficult to know that we are asleep. We think we are son or daughter of so and so, our names are this or that, we are happy-sad, rich-poor etc. But absolutely speaking, that may not be true.

Now, knowing all this is fine and simple but when this knowledge really hits you and when you actually question your life, your self and what all has passed and what is really happening in front of you and that what you might think about all of it may just be a dream and will pass away anytime into nothing, you are shaken up into a mode of contemplation which trembles the very foundation on which you based all your ideas of reality about yourself and about what is around you. It might happen in an unknown moment when you never thought of it and suddenly you are so aware of what you have known for so long but never really felt it, it will come out of nowhere, something you've never seen or experienced.