When you are manipulating within physical reality, you have a fairly simple set of rules to serve you. Within dream reality there is greater freedom. The ego is not present.  The waking consciousness, dear friends is not the ego. The ego is only that portion of waking consciousness that deals with physical manipulation.

Waking consciousness can be taken into the dream state; the ego can not, as it would falter and cause immediate failure. In your experiments you will meet with various conditions, and until you learn to control it may be difficult to distinguish between them. Some you can manipulate, some you cannot.  Some dream locations will be of your own making, and others will be strange to you. They will belong to other dimensions of reality, but you may blunder into them.

It is quite possible for a dreamer to visit other planetary systems of past, present, or future in your terms. Such visits are usually fragmentary and spontaneous. It is best that they remain so. Take advantage of them when they occur, but do not attempt such endeavors yet, however, as many difficulties are involved.

The Seth Material - Dreams-A Pseudo Demon - page:211

When you dream of others, they know it. When they dream of you, you know it. There would be nothing to be gained, however, in conscious awareness of these conditions at this time.

The Seth Material Session #254