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has an apology to make.
"I have coffee breath," the singer says as she curls up on a couch. "Sorry if it bothers you!"
Lately, she has really needed the caffeine: Perry is in the midst of the U.S. leg of her Prismatic tour; running through next March, it will bring her to Australia and across Europe.
"It's taking all my energy," she says of her worldwide neon-tinged trek.
But that hard work is paying off.
Her fourth album, Prism
, gave the singer her best debut yet, and the lead single "Roar" has gone platinum six times.
"A lot of times I write these songs because I need to reinspire myself," says Perry.
"When I was writing 'Roar,' I was like, 'I need to find my voice again. I need to be heard. I need to find that empowering thunder in my chest again.'"
Perry, now single since her on-and-off relationship with singer John Mayer ended in February
, is taking that new burst of confidence with her as she enters the next phase of her life: her 30s.
"I still feel 13 on the inside," she says of hitting the milestone in October.
"Birthdays are a big thing for me. We always have a themed party. It's a good excuse for me to bring my friends together and go buck wild."
But don't expect her to go too crazy. Perry – who recently teamed up with Staples and DonorsChoose.org for the Make Roar Happen campaign, which benefits teachers – has some very practical wishes as she enters the next decade of her life.
"I just want to be able to continue to stay self-aware and as unaffected as possible," Perry says. "I just want to stay authentic and keep dreaming my dreams."