I had so much fun talking about our good old days with a person I had not seen for a long time.
"懐かしい人に会って思い出話に花が咲いた"
懐かしい人、しばらく会ってない人 a person I had not seen for a long time
述語動詞の時制が過去形なので過去完了となっています。
思い出話に花が咲いた I had so much fun talking about our good old days
I had so much fun talking about our good old days with a person I had not seen for a long time.
I ran into someone I hadn't seen for a long time yesterday, and we shared a few good old memories.
I saw an old acquaintance the other day, and we soon began reminiscing about the good old days.
ーI ran into someone I hadn't seen for a long time yesterday, and we shared a few good old memories.
「昨日しばらく会っていなかった人にばったり出会って、思い出話しに花が咲いた」
to run into で「〜に偶然会う」
someone I hadn't seen for a long time で「ずっと会っていなかった人」
to share a few good old memories「古き良き思い出を分かち合う」を使って「思い出話に花が咲く」を表現できます。
ーI saw an old acquaintance the other day, and we soon began reminiscing about the good old days.
「この前、古い知り合いに会って、私たちはすぐに古き良き時代についての思い出を語り始めた」
acquaintance で「知り合い」
to begin reminiscing about the good old days「古き良き時代についての思い出を語り始める」＝「思い話に花が咲く」
ご参考まで！
日本 
カナダ 
