United's clinical 2-0 win over Newcastle United in Sunday's League Cup final at Wembley ensured manager Erik ten Hag will have delivered silverware in his first season.
Considering where United started the season, it has been a rapid transformation and De Gea was full of praise for the former Ajax manager.
"It's difficult to describe and I'm emotional because it's been so long without a trophy," De Gea, who kept a club record 181st clean sheet on Sunday to surpass Peter Schmeichel, said.
"The start for a new era. The team is ready for everything. We showed today we can win trophies. So let's enjoy the moment but go again. I feel the mentality of the team is a winning one.
"We are winning games and people are having an impact from the bench too. Let's keep the momentum going."
De Gea was part of the last Manchester United side to win the Premier League in 2012-13 and was also in goal when United won the Europa League and League Cup in 2017.
With United still in the hunt for the Europa League, FA Cup and Premier League title, confidence is soaring.
Luke Shaw (27), whose superb free kick allowed Casemiro (31) to open the scoring on Sunday, summed it up.
"It feels amazing. We want to create our own history with the new manager and today was the start of it," he said.
"We enjoy tonight and then back in training.
"We are still in all the competitions and getting the taste for this, we want more."
Marcus Rashford (25), whose shot was deflected in by defender Sven Botman (23) for United's second goal, epitomises United's resurgence under Ten Hag, having scored 16 goals since the World Cup.
He said Sunday's win had given the squad a taste of success that they are hungry to repeat.
"It is massive for us to be involved in these types of games and something we have missed as a club, hopefully it pushes us to keep going," Rashford said.
"The hunger is to have more moments like this. I've been in finals we have won and lost and when you win it is massive for the club and as individuals and part of our and the club's history and we want to keep adding to it."
