The stunning victory had particular resonance for the 26-year-old, who was part of the PSG team that lost 6-1 to Barcelona to bow out of the 2017 Champions League.
Moura said it had all caught up with him after he was shown a Brazilian TV clip of his decisive 96th minute third goal for Spurs soon after the final whistle in Amsterdam.
"When I saw the video and heard the commentator, it was impossible to keep my emotions in," Lucas said in an interview with The Guardian. "I remembered the 6-1 Barcelona game and the struggles I have had in my life.
"It has been my dream to play in the Champions League final and to win one, and now I have the opportunity. The dream is real, that's why I became emotional.
"It is impossible to describe the feeling when my hat-trick goal went in but I believed until the last seconds that we could do something."
PSG's loss to Barcelona two years ago was particularly disappointing as the French side had held a 4-0 lead after the first leg of the round of 16 tie.
"I can now say I know the two sides," Moura added. "The Barcelona game was the worst feeling of my football life. When I got home, I cried all night.
"I said that I never wanted to feel like that again and so I worked harder to have another feeling and against Manchester City (in the quarter-finals) and then (against) Ajax it came.
"The Ajax game was the best feeling of my football life. Moments like Barcelona must motivate you."
(Reporting by Rohith Nair in Bengaluru, editing by Nick Mulvenney)
