Ollie Watkins scored a first half hattrick as the Reds became the first reigning English champions to concede seven goals in a league match since 1953.
“It was unexpected but it happened tonight,” said Klopp.
“We put all our rubbish things and mistakes in one game and hopefully we can start again.”
Liverpool’s high line was torn apart by Villa’s counterattack, while the absence of goalkeeper Alisson Becker to injury and Sadio Mane due to a positive coronavirus test was notable.
The Reds were not beaten until their 28th league game in romping to the title last season and had won their opening three games of the new campaign.
Alisson’s absence made a telling impact after just four minutes to get Villa in front as Adrian’s poor pass was seized upon by Jack Grealish, who squared for Watkins to score his first Premier League goal.
“The first goal had an impact, but it shouldn’t,” added Klopp.
“Adrian made a mistake but we conceded goals like this in the past. We lost the plot then.”
Despite a two-week layoff until they play again, Klopp has little time to make corrections on the training field with most of his squad away on international duty.
On their return, Liverpool travel to top-of-the-table Everton, who will be looking to win a Merseyside derby for the first time in a decade.
“I would love to have a training session tomorrow and Tuesday and to talk about it, but the boys go back off to international duty,” said Klopp.
“Hopefully they come back healthy and we use the two days to prepare for Everton.”