The Irish rockers, whose first two albums have debuted at number one on the official album chart, admitted that they didn't feel successful until their sophomore effort Science & Faith topped the charts earlier this year.
"You can't predict what's going to happen next. You don't want to get cocky because we spent so long trying to get where we are now that we don't want to sit back and think that we've made it," drummer Glenn Power told Bang Showbiz.
"In many ways we don't feel like we've made it at all. We feel like we're on our way now - we feel like we've got started.
"For us to get the second album to number one was a validation of what we're doing and, as musicians and being in a band, it's such a great stamp on your career to say 'we've done this twice now', so maybe we're doing the right thing."
He continued: "It secured our future in our minds and made us realise that we can actually make a career and a life out of this. It's what we've always wanted, so to finally get to a point where we can be a success it's such a beautiful thing."
The band's 2008 hit 'Breakeven' recently peaked at number 12 on the US Billboard singles chart.