David Wagner said Huddersfield Town made too many mistakes at both ends of the pitch as they suffered a first defeat in six Championship games.
Town are down to 17th in the table after falling victim to a James Wilson goal and having right-back Tommy Smith red carded.
"We can learn a lot from this defeat," said the head coach. "At first we were playing the right way, and for parts of the game we did well against one of the better sides in the league.
"But to beat this kind of side, we are not allowed to make such simple mistakes. We made too many errors in not using our chances and not defending well enough.
"The way Brighton got their goals, especially the second one, was much too easy. We should have cleared the ball to the stands in the build-up and given ourselves chance to reorganise.
"But we like to learn and we are on our way, and in the future, we will beat sides like this. My squad are very open-minded.
"Our unbeaten sequence might have ended but now it is up to us to start a new one, beginning at home to Cardiff City next Saturday."
Town will be without both Smith and skipper Mark Hudson, who has reached 10 bookings and must serve a two-match ban, against the South Wales side.
But Wagner, who said he thought new forward Karim Matmour was "okay" on his Town debut as a substitute, insists he has enough players to cover.
"We will find solutions," he insisted. "We have a clear week to work in the training ground and we will be ready."
