When you are sitting silent, but then suddenly are becoming absent in mind, you discover how the thinking sucks life and energy out of the present.
Past and future become reality, while reality becomes emptiness.
You discover how the thinking analyzes, separates and divides in order to evaluate, understand.
You discover how the thinking removes the mind from the Now, and creates the inner calculator, the experiencer or the thinker, who compares with earlier, or who hopes and desires something else; the thinker, who slides off from the Now´s facts.
And you discover how the Now´s facts, seen from the thinking´s past and future, can become a problem.
You have pure and simple discovered the cause of your problems.