Mithya and Satyam

The experience of something does not automatically portend the reality of the experienced .
Dream is also very much experienced , while the experiencer of the dream is very much real and present , dream itself cannot be said to be 'real'.
It is only while dreaming that one might consider the dream to be real. And hence invest in 'i am the person undergoing this experience ' , as in a dream one takes the dream to be real. But on waking state I say ' this waking state is 'real' , dream was unreal.

Vedantic wisdom on the other hand , does not even consider the waking state also as absolutely real. It makes a strong statement of fact, that affixes the waking state also a lower degree of reality , as compared to atma or brahman which alone is absolutely real.
Now what does real mean, real for one has to exist and exist as it is , determinably so. It must be non negatable at any stage.

If we take a table, a table loses its reality to wood . Functionally its a table has its utility as a table , but it's reality belongs to wood , which alone can be said to be 'real'. Further if we look at wood also, wood in turn is a name given to the wood form and material and has its reality in cellulose . Like this we can go on. We see the experienced objects do not have a reality of 'their own ' .
On the other hand , we cannot say objects experienced are non existent , such as horn of a man. Horn of a man is non existent, if at all only an imaginary horn of a man can be talked about. There is not even a relatively real horn of a man. However objects that we see such as a tree , sky, our own body etc . have a relative reality . Though when analysed they do not have a reality of their own being made of parts other than itself , such as a tree is made of 'non tree' parts, which themselves are made of further parts . Where is that which is absolutely real , which alone lends reality to all that 'is'. This reality has to be unchanging with time , space , shastra says it is a non dual reality.

We can argue infinite causes , which is where logic seems to take us , but it's not a complete logic as it ends in infinite regress. Cause of b is a, cause of a is c, cause of c is d and so on till ad infinitum. We cannot say cause is unfindable , unknowable. An unknowable cause presumes a non existent cause. What is unknowable cannot exist, as existence automatically implies knowability. But whatever is knowable we have already seen how it has a dependant existence only .

So what shastra says , that atma the self evident , consciousness that is present in all 3 states of waking dreaming and sleeping , knower of space itself , sakshi chaitanyam , when it says sakshi chaitanyam alone is absolutely real, and all that we experience as 'exists' , which we have seen has only dependent existence , gains existence from sakshi chaitanyam which is non dual independent , existence , consciousness principle.
This shastri knowledge is assimilable , logic doesn't refute it , cannot refute.