I knew you looked like someone, and now I realize it's Al Pacino.
I knew you reminded me of someone famous, it's Al Pacino.
この場合、次のような言い方ができますよ。
ーI knew you looked like someone, and now I realize it's Al Pacino.
「誰かに似てると思ったら、アル・パチーノだ」
ーI knew you reminded me of someone famous, it's Al Pacino.
「誰か有名人に似てると思ったら、アル・パチーノだ」
ご参考まで!