| Quote #4
…and I remember once saying to him as I braved the mockery of his encouraging nods that, were I a writer, I should allow only my heart to have imagination, and for the rest rely upon memory, that long-drawn sunset shadow of one's personal truth. (22)
If memory is a "shadow" of truth, then we have to question its accuracy. Victor is constantly calling into question the validity of his memories and forcing us to doubt his narrative.
| Quote #5
Was there any practical chance of life together with Nina, life I could barely imagine, for it would be penetrated, I knew, with a passionate, intolerable bitterness and every moment of it would be aware of a past, teeming with protean partners. No, the thing was absurd. (31)
Victor defines his relationship with Nina as a series of past events. Because she exists for him in memory, her presence is always mystical, and the thought of a future is impossible. In a way, the rules of the story dictate her death – she isn’t allowed a future.
| Quote #6
Fialta consists of the old town and of the new one; here and there, past and present are interlaced, struggling either to disentangle themselves or to thrust each other out; each one has its own methods: the newcomer fights honestly […] whereas the sneaky old-timer creeps out from behind a corner in the shape of some little street on crutches or the steps of stairs leading nowhere. (32)
Looks like setting is cleverly crafted in "Spring in Fialta," as if we expected anything less from Nabokov. You can read more in Shmoop’s discussion of setting, but for the time being we can note that Fialta, like Victor and Nina’s relationship, is a struggle of the idealist past vs. the very real present.