The British driver is yet to win a Grand Prix this year after claiming his maiden world crown for McLaren last term and is frustrated that poor reliability has hindered his campaign.
In an interview with BBC Sport, Norris said: "Expectations were high from my side, from us as a team. Rightly so. But it's just been more difficult than we would have wanted. From a power-unit side of things and from a car side of things.
"Should have won in Miami. So it's not like we're having a dreadful season. It's been dreadful for one reason, reliability and issues. That's been the biggest letdown of the whole year.
"But apart from that, the pace has not been terrible. And we can still go into weekends now with some confidence that we can have a good weekend. And that can mean a podium. It means extracting absolutely everything and being perfect the whole weekend. But it is possible."
Norris explained that his world championship success last year has made it slightly easier to deal with this season's disappointments.
The 11-time Grand Prix winner said: "I'm still able to probably smile more, definitely able to smile more now even through the tough times because of last season. So, I'm still basking in the moments of last season.
"But every driver is in it now because they want to win now. I'm not going to be happy finishing fifth, sixth, fourth the whole season. So, I enjoy winning. I want to return to winning. And that's my goal currently."
Norris won his home race at Silverstone en route to the world title last year and is ready for a special British Grand Prix this weekend – even though he will "need a hell of a lot of luck" to take the chequered flag again.
He said: "The British Grand Prix is one of the best races of the season. But then it's my home race. It's our team's home race. I'm champion. There's just a lot of beautiful things to look forward to.
"It will be the race that I will miss the most one day. When I retire. In many years' time. This will be the thing I miss, the fans. That kind of feeling of trying to provide for them in terms of giving them a win and providing for your country.
"That's a pretty awesome thing. Therefore, I know I need to really take it all in as much as possible."
