When a person loves someone as he did, you can ask them to say the first thing that comes to mind
and no matter what the first thing will always be them.
The one that rests in their chests, taking up room to make their hearts beat like crazy and their breaths puff quick.
They will smile a little at your question and give a sensible answer instead because the answer cannot always be the same.
Though for them it is.
That is how he loved her.
Every day, every word, every thought was her.
But unknown to him was her thoughts of him.