I only think about
I only think of him.
I only think of her.
I can think of nothing but you.
Je ne pense qu'à l'Alaska, à présent.
All I can think about now is Alaska.
Je ne pense qu'à ça depuis que c'est arrivé.
I haven’t been able to think about anything else since it happened.
— Rebecca (1940)
Tu sauras que moi, je ne pense qu'à toi.
You should know that I think of nothing but you.
— The Umbrellas of Cherbourg (1964)
En ce moment, je ne pense qu'à Liu Xuan.
Right now, I can think of nothing but Liu Xuan.
— The Mermaid (2016)