All kinds of signals and hints have with Man as a communicative being to do.
Signals and hints therefore only come to expression in the relationship with the surrounding world, or differently said: in the Now.
But the conscious mind is so occupied by its daily activities, annoyances, anxiety, that it is unable to receive signals and hints in the course of the day.
However in the sleep there is a resting state, which also is there even when you are dreaming.
When the superficial mind falls to peace, then this resting state makes it possible for the many layers of the mind to project themselves to this, and then you are dreaming.
It is in this state you can receive signals and hints.
The same is happening when the conscious mind is going into a meditative state.