The original comment had a kind of upward twist at the end, due to the cognitive dissonance introduced by the poster’s use of the colloquial phrase “Thanks for the ___, Subway guy”. What read as a mostly older, serious comment was upturned on its head at the end by the change in tone.

I think the OP here was responding to the change in tone which signaled that such dry wit of response was “allowed” on such a post.

Had OPs comment not ended with some sort of puzzling naive phrasing and twist at the end, I doubt he would have felt comfortable with his dry cynical joke.

In some sense, he’s trying to cancel out the overly positive naive tone introduced by OP at the very end.

Equanimity and balance is not so bad. OPs weird ending belied a sort of youthful immaturity which struck counter to the wisened, aged tone with which he had cumulatively relayed with his story thus far.