David Moyes's team ran out 5-0 winners in a display of attacking football to leave Bayer fighting to get into the next round from Group A.
"United taught us a lesson today," Hyypia told UEFA.com. "They took clinical advantage of our mistakes. I hope that a game like this is good for the future and that we are able to learn from it.
"Our performance wasn't that bad until we conceded the second goal. We then let our heads drop and didn't believe we could start a comeback. It wasn't the game we thought we were going to play."
Leverkusen are second in the Bundesliga.