The narrator establishes a preference towards seclusion in the first verse. We know the narrator is not fervently searching for a relationship.

Verse 4 pairs with the last two lines of verse 2 to indicate the narrator has historically used their forgetfulness or time as a defense mechanism to forget previous (potentially painful) relationships.

What ensues is encapsulated by the chorus,

The best time of all
I was not looking for it

Verse 4 does offer a resistance to our narrator’s reservedness. It is clear, for the time being, the narrator cannot get the memory out of their head.

Memory likes to talk a lot
I don’t care ‘cause I know I’ll forget it
When I put my fingers up
All the sparkles wouldn’t let it

Perhaps this indicates things were truly great and the narrator will be motivated to pursue again or the narrator has forgotten their historical period of nostalgia after “it’s over”–but right now, it’s impossible to forget.