Tottenham enjoyed an emphatic 4-0 win at Stoke City on Saturday.
Having taken five points from their opening three fixtures this term, Pochettino's side rediscovered the scintillating form they showed on that April night as Heung-Min Son scored twice and Dele Alli and Harry Kane both opened their season's accounts.
"I think that after four games unbeaten you can see that the players are thinking about the new season, the new challenge," Pochettino said.
"We forget the past. We worked hard to forget last season and focus on the present. After four games we are unbeaten and you can see that the team has recovered.
"We need to improve now. Pre-season was tough. Now we need to work hard, improve and stay together."
Kane's goal, the fourth of the afternoon, was his first in 10 for his club and country, dating back to England's pre-Euro 2016 friendly win over Turkey in May, and also his 50th in the top flight in just 87 appearances.
"It was very important for him to recover the feeling of scoring," Pochettino added.
"Always the strikers are worried when they don't score but now he feels happy, we feel happy. I think that was a perfect victory for us."