게 지나가다

how time or things went by

Describes the manner of passing: 빠르게 지나가다 "go by fast", 쿨하게 지나가다 "walk past it coolly", 그렇게 지나갔고 "it just went by like that". 어떻게 지나갔는지 — "how it went by" — turns up twice here, both times with the speaker unable to recall any of it, which is the standard thing to say about a blur of a day. Compare 고 지나가다, which is about you doing something and moving on rather than about how the passing felt.