This was written about a real dream I had.  I took very few liberties, so it is quite close to the actual dream.

And so I slept. And as I slept, I dreamed I was in a fantasy world, beautiful and green. But my world was small, as I soon discovered, for I was on an island, surrounded on all sides by a deep ocean. For a moment I despaired, thinking there was nothing but ocean beyond. But this was allayed when through the distant haze I conceived of several islands, in view but beyond any distance I could swim. Despair returned and the rest I cannot remember.