Both waking and both dreaming; such a doubt
Confounds and clouds our moral life about.
But whether wake or dreaming, this I know,
How dreamwise human glories come and go;
Whose momentary tenure not to break,
Walking as one who knows he soon may wake,
So fairly carry the full cup, so well
Disordered insolence and passion quell,
That there be nothing after to upbraid
Dreamer or doer in the part he played;
Whether tomorrow's dawn shall break the spell,
Or the last trumpet of the Eternal Day,
When dreaming, with the night, shall pass away.
I feel here the author was trying to express that maybe Life itself is the dream, and when awaken your dream “shall pass away”, along with all the other ideas or desires you had. Or maybe it’s just stating that your dreams can be about anything, but when you wake up, your back to reality and the harsh realities of life.
The Dream Called Life