Mario Mandzukic's 81st-second strike inspired Atletico to a 1-0 victory over Real Madrid in the second leg of their Supercopa tie at the Vicente Calderon.
The result - Atletico's first win at home to city rivals Real in 15 years - gave the Spanish champions a 2-1 aggregate triumph.
Speaking post-game, Simeone said lifting the Supercopa trophy for the first time since 1985 was the confidence boost his team needed ahead of the club's La Liga title defence.
Atletico kick-off their league campaign at Rayo Vallecano on Monday.
"The Super Cup is a title that many of us in the club didn't have and it makes us very happy," said the Argentinian, who has now claimed five trophies since replacing Quique Flores in December 2011.
"It awakens our enthusiasm, and life with enthusiasm makes us all much better.
"It's a source of pride for our people, for our players and for our work."
Simeone added: "Both at the [The Santiago] Bernabeu and here the team has worked well and that's what's given us the Super Cup."
The Madrid derby was marred by a touchline incident in the first half involving Simeone.
A raging Simeone was sent to the stands in the 26th minute for appearing to slap the fourth official on the back of the head after reacting angrily to the referee's decision not to allow Juanfran back on the pitch in sufficient time.
Simeone, though, apologised for his actions during his post-game conference.
"Apologies are offered when one makes a mistake that shouldn't have been committed," he said.
"I exaggerated the request so Juanfran could go in fast and the referee decided to take me out of the game."
