Hooiveld says that the club were punished for a lapse in concentration on Saturday, and the former Celtic centre-back is adamant that Saints will learn from the match.
"You think you're in control of the game, then one break and it's a goal. That is something that we have to be very careful of, be very concentrated and also as a unit we have to progress in that," said Hooiveld.
"The thing that I now realise, two games in, is that as soon as people drop a couple of percentages in their concentration you are going to get punished, like the first goal for example.
"We controlled the game quite okay until that moment, then you know it's going to be difficult. They will be behind the ball and it's difficult to break them down and the second goal you don't really count it."
Saints host Manchester United at St Mary's next Sunday.