Spurs slumped to their third defeat in five games in Europe's elite club competition.
Spurs slumped to their third defeat in five games in Europe's elite club competition when they went down 2-1 to Monaco at the Stade Louis II to end their hopes of reaching the last 16 with a group game still to play.
The north London club needed a point to stay in the hunt and saw Harry Kane's 52nd-minute penalty bring them level just four minutes after Djibril Sidibe had put Monaco ahead.
However, the principality side -- who saw Radamel Falcao have an early penalty saved by Hugo Lloris -- immediately went back in front through Thomas Lemar before holding on to progress as Group E winners.
Tottenham have now won just one of their last nine matches in all competitions but Pochettino said: "I think it was a good challenge for us to compete in the Champions League and show our real level.
"We are competitive in the Premier League, because we are unbeaten after 12 games and near the top.
"It is good for us to learn and try again in the future. Maybe if we are in the Champions League next season we will need to make some changes.
"After two and a half years we have reduced the gap to the top teams in the Premier League. To be competitive in both competitions we need to show more and also add more quality to our squad.
"The Champions League demands the same energy as the Premier League and I think we have struggled a little with that.
"I am disappointed but this has been a great experience for us."
Tottenham, who finished third in the Premier League last season, have been a club on the up under Pochettino and the Argentine is still looking at the bigger picture of turning them into Champions League regulars once they move into their new stadium in 2018.
"Our project is not finished today," said the 44-year-old.
"Many weeks ago I said these are our first steps. The objective is to be in the Champions League regularly when we have the new stadium."
Tottenham will host CSKA Moscow at Wembley -- where they have lost two out of two games so far -- in their last group match next month needing a draw to secure a consolation spot in the Europa League after Christmas.
"It would be good for the club to get into the Europa League and try to go further in that competition," he said, dismissing suggestions that competition would be a hassle they could do without.
Before that Tottenham have a trip to Chelsea for a London derby on Saturday that will be crucial for their Premier League ambitions -- they are currently four points behind Antonio Conte's table-toppers in fifth place.
"We feel bad now but tomorrow is another day to look forward and be optimistic. We need to compete on Saturday against Chelsea, lift the players and try to go there and win the game."
Meanwhile, Monaco go through along with Bayer Leverkusen after another impressive performance and few sides will fancy coming up against Leonardo Jardim's talented young side in the last 16.
Monaco have eliminated the likes of Manchester United, Chelsea and Arsenal in the Champions League in the past and this was another memorable scalp for a team that began this season's competition in the third qualifying round in July.
"I am very happy to be through and to have won the group but also with the performance of the team. I think we played really well," said Jardim.
"The players have shown lots of great quality and intensity over the last four months."