Did Levan remember his grandmother? Absolutely not. He had no memory of his grandmother at all.
When his grandmother sacrificed herself to achieve peace between Wrelloven and Grinia, he was only a few months old, so naturally, he had no memory of Queen Everlin who was the ruler of the kingdom at the time.
However, his parents always told stories about his grandmother since he was a child, not wanting to see their child forget the one who had been a hero for the kingdom. That was why Levan felt a connection with the late Queen even if he had no memory of her.
When Queen Richenza suddenly killed herself as she threw her own body into the lake, Levan immediately thought that something was going to happen in the lake, but instead of running away as everyone else did, he chose to stay near the lake for some reason.
And the reason was none other than his desire to meet his grandmother.