Maybe he was better off not knowing the truth.
Well, he thought about it. If Sakura had told him something like she had loved him, and then she lost her memories of him, not knowing who he was, it would be horrible. To know the person you loved had loved you, and then did not even know who you were all in the same day, would have to feel horrible, especially if you love them back. Luckily, in his opinion, this was not the case.
But then, what if that small happiness of not having an unrequited love would be bigger than the pain? Could he have been somewhat happy enough to be able to continue the journey, even though she would not love him back anymore? Maybe, but he would never know. The chance to know had long past, lost in a whirl of happier times.
Still, he was selfish. He wanted her to love him. He wanted his love to be requited. And yet, as he looked over at her giggling with the others, he knew it would never be.
Kurogane-san was a good example. He was handsome, strong, and could protect easily. He was a ninja bodyguard for another princess. Or look Fai-san. He had never said anything, but it was easy to tell that he was a very powerful wizard. Either of them would be better for the princess, rather than a no-name archaeologist who could barely protect himself, not that he did not love his father of course.
It was simple. She was royalty and he was no one. There was no way that she could have ever loved him like anything other than a close friend or brother. Still…
Looking back at her smiling face, he really was better off without knowing the truth.