Your author uses the idea of the persona of Ertugrul Osman to express the concept of having lost something, for few of us, like him, have ever had to relinquish an empire.
This was Ertugrul's fate, for he was born just as the Ottoman Empire he'd have ruled began to take its last shallow breaths, and it had expired before he had the chance to steer it.
The choices open to Ertugrul after this setback are the choices open to all of us after having lost something dear to us, or, perhaps worse still, having seen a dream dashed just at the point when it was close to being realised.
Ertugrul could have:
1) shrugged his shoulders at the loss and carried on without a second thought, in a manner which is uncommon to most of us. The Ottoman state is dead, but I persist without it.
2) accepted his lot with a straight face, beneath which writhed feelings of devastation that were never properly dealt with.
3) summoned such rage that he set about reconstructing the empire from its roots, and made it his life's work - and when there is such an all-consuming imperative, it almost ceases to matter whether or not one succeeds.
4) split his mind into two parts - one which 'knew' the empire was lost, and which more often than not held sway when Ertugrul and the world interact. Sometimes, though, it was easy to believe the falsehood that all was as it had ever been. The Sublime Porte continues to radiate its influence across a vast sweep of the globe, and the culture built up from a tribe of 13th-century Muslim wanderers still strikes fear into its enemies and joy in its acolytes.
The next morning, you wake up with heaviness in the head, and in the limbs, and in the soul, because it was nothing more than a dream. Like being drunk, you can't properly remember all that happened to you last night, and this amnesia prevents the full horrors of your own mental state being drawn into the light.
