The Germany captain is hugely excited about the curtains coming down on their European campaign, which kicks off on Saturday, as he has fond memories of past meetings with Portugal
Joachim Low's men were runners-up in the previous edition of the competition in 2008, and endured further heartbreak in the 2010 World Cup, where they were beaten by Spain in the semi-finals.
However, the Bayern Munich defender is eagerly awaiting the opportunity to make up for previous disappointments, and feels his side are well-prepared to succeed in the tournament.
"The tension is slowly rising," he told DFB.de. "I could tell that the European Championship had truly started by our reception in Poland.
"The opening game is on Friday, and we are looking forward to our first mission the next day. We have been working for two years for this moment. It's time to get going.
"Everything is very positive. If you look at the talent and the quality in the team, we're a top level team. In my opinion, the preparation has gone very well so far.
"We are all working to achieve our goal. We were third in the World Cup and runners-up in the Euros. These are great achievements, but we want more.
"But we know that this won't happen by itself. There are no guarantees that we will eventually win the title. Behind success is hard work. That's what we need: we'll do it.
"But I'm optimistic: this team has the talent, the quality, and the will."
Germany's first game of the championship is against Portugal, whom they beat 3-2 in the quarter-finals four years ago, as Lahm reminisced his previous encounters with the Seleccao.
"I don't just think about the quarter-finals of Euro 2008, but also about the the third place play-off in the  World Cup in Germany," he continued.
"Both were very nice experiences for me and the team. So, when I think of Portugal, I'm filled with positivity."
Lahm has the chance to overtake Fritz Walter as the man who has captained Germany on the most occasions, and the 28-year-old admits it has been an honour to wear the armband for his country.
"That's unbelievable. Fritz Walter is a legend," he enthused. "The team captains are always greats in Germany. Now I'm part of this series, and I'm filled with pride.
"I have grown into this role, and am very happy to captain the national team."
Germany and Portugal kick off at 20:45CET on Saturday.