I sometimes get lost in reverie about the good times I had in high school.
"楽しかった高校時代を思い出し空想にふけることがある"
- I sometimes get lost in reverie about the good times I had in high school.
- Thinking of my fun high school days gets me lost in reverie.
- I get put into reverie when thinking about my good high school days.
I sometimes get lost in reverie thinking about the good old days from high school.
I sometimes find myself daydreaming about the fun times I had at high school.
reverie を使って言う場合：
ーI sometimes get lost in reverie thinking about the good old days from high school.
「時々、高校の古き良き時代を思い出し、空想にふけることがある」
to get lost in reverie で「空想にふける」と言えます。
to daydream を使って言う場合：
ーI sometimes find myself daydreaming about the fun times I had at high school.
「時々気がつくと、高校時代の楽しい時間について空想にふけっている」
to find oneself ... で「気がつくと…している」
to daydream で「空想にふける」
ご参考まで！
アメリカ合衆国 
カナダ 
