I practiced our new fighting game alone after we agreed to learn together. Was that unfair?

My brother asked how I knew the move that kept catching him. I said I'd spent two evenings in the practice mode. He put down the controller and said, "I thought we were both new at this."

We had bought the game to learn together. We hadn't said we could only play together, but I had liked the idea that we would discover the controls at the same pace. Then I had a free evening, enjoyed practicing, and didn't mention it before our next matches.

He lost six in a row and stopped wanting a rematch. I offered to avoid the move, which sounded as if I was offering to play badly. That annoyed him more.

Do I owe him an apology for the practice, for keeping it quiet, or only for assuming our matches would still feel the same? I want room to enjoy the game on my own without turning the thing we bought together into another lesson from me.