Time in The Gift

One of the main themes of The Gift, it appears, is remembrance. Time. Nostalgia. A return to childhood. I’ve picked up 2 motifs in the book: keys (keys, lost keys, forgotten keys, keys for the new apartment, key to wake up “the tropical songbird”, keys in Chernyshevski’s maid’s hand, etc.), and clocks and watches (a poem about a man from the clock shop, a pendulum clock that seems to measure his insomnias, a misbehaving watch, giant clocks in watch-makers’ shops, etc.). What can be more fitting? 
But here is a passage about time that is quite something else, and particularly interesting: 

“Yasha and I had entered Berlin University at almost exactly the same time, but I did not know him although we must have passed each other many times. Diversity of subjects—he took philosophy, I studied infusoria—diminished the possibility of our association. If I were to return now into that past, enriched in but one respect—awareness of the present day—and retrace exactly all my interloping steps, then I would certainly notice his face, now so familiar to me through snapshots. It is a funny thing, when you imagine yourself returning into the past with the contraband of the present, how weird it would be to encounter there, in unexpected places, the prototypes of today’s acquaintances, so young and fresh, who in a kind of lucid lunacy do not recognize you; thus a woman, for instance, whom you loves since yesterday, appears as a young girl, standing practically next to one in a crowded train, while the chance passerby who 15 years ago asked you the way in the street now works in the same office as you. Among this throng of the past only a dozen or so faces would acquire this anachronistic importance: low cards transfigured by the radiance of the trump. And then how confidently one could… But alas, even when you do happen, in a dream, to make such a return journey, then, at the border of the past your present intellect is completely invalidated, and amid the surroundings of a classroom hastily assembled by the nightmare’s clumsy property man, you again do not know your lesson—with all the forgotten shades of those school throes of old.” 

(Ch.1)