"Also, it's very important that we don't let these incredible achievements affect us or make us complacent," he adds. "We've got to build on that success and get better."
That's why, explains Tomlinson, he and his bandmates have co-written three of the songs on their new album, Take Me Home, including the sun-kissed Summer Love and playful Last First Kiss.
"It's important for us to put as much of ourselves into the band as we can, so that's why we've written a few songs on the new album. We tried doing that with the first album too; we tried to contribute as much as we could and be ourselves as much as possible but obviously that was hard because we were new to things and not sure how the whole recording process worked.
"With the new album, there's definitely more of ourselves on it, because not only have we written some songs, but we understood the process a bit better, so we felt more comfortable in terms of recording the album," he says.
Aside from co-writing three tracks, One Direction have re-enlisted the help of singer-songwriter Ed Sheeran, on their latest single Little Things and the catchy Over Again after poaching his song Moments for their debut album.
They also reteamed with Swedish hit-makers, Carl Falk, Rami Yacoub and Savan Kotecha - who wrote and produced their breakthrough hit What Makes You Beautiful - for the single Live While We're Young and a clutch of other killer cuts, including Change My Mind. Throw in writing/ production help from pop veterans Shellback and Dr Luke, alongside McFly's frontman, Tom Fletcher, on I Would and Take Me Home is a slightly tougher, rougher pop blast than its predecessor.
"It is a little edgier and grittier on a few tracks, which is why we're really proud and excited by it," says Tomlinson, smiling effusively. "But overall, it's pretty much more of the same: musically, it's not that different."
Accordingly, there's still One Direction's trademark soaring harmonies, catchy-as-a-cold choruses and hummable, bubblegum pop, as breezy lead single, Live While We're Young shows with its exuberant message of enjoy your youth and party-hard - not a particularly difficult challenge, you'd imagine, when you're a member of the biggest boy band in a generation.
"Live While We're Young' is definitely a motto for us," says Tomlinson, laughing.
"The way I've always seen it, growing up, is you're only young once and there are some things that you can only get away with when you're young, by blaming them on being young! That's what the song's about."
Ironically, despite their popularity - and the possibilities it entails - One Direction aren't taking full advantage of their position at the pinnacle of pop, because they're not out every night partying, on the prowl or milking their fame for all it's worth.
Instead, their idea of "living while they're young" is more mild than wild.
"Yeah, all of us have been pretty sensible," he says, shrugging.
"Obviously, there's a side to it which is going out, partying and staying up all night, which can be fun. And also, with our success there are opportunities of being able to sleep around - if you wanted to - because we do get a lot of young girls coming up to us. Actually the new album [being called] Take Me Home kind of plays on that: you could interpret it as being in a club and saying to someone 'come home with me ...'
"But there's a double-meaning too: it's also about us being on tour, where we're away for six to eight weeks, and saying 'take me home' because we just want to be home. It's recognising that being in a band is great, but also a lot of hard work. That's something we didn't appreciate, at first.
"Being on the road, touring, can be really tough," he adds, sighing.
But this was what they signed up for. The band was thrown together, after they didn't make it through the qualifying rounds of the UK's 2010 season of The X Factor, at the suggestion of judge and Pussycat Doll Nicole Sherzinger.
"For me, personally, my goal with X Factor, was to get through to boot camp. But I didn't think I was going to be voted out so quickly, because I thought I could rely on my voice to get me through. So, when they threw the offer of putting together a band, I was like 'Okay, yeah, let's do it.' I think that's how we all felt, because we realised we'd been handed a lifeline.
"I think we were incredibly lucky to be put into the band during X Factor, rather than carrying on as solo artists. That's because, even if we take everything out of the equation, like fame or success, we're basically five people who didn't know each other at the time, but now we're like brothers, who get on so well and always support each other."
Lowdown
Who: One Direction, the world's biggest boy band
What: Second album Take Me Home, released November 13
Also: Playing Saturday 12 and Sunday 13 October 2013, Vector Arena, Auckland
- TimeOut