"Last year was a quite an eye opener," he told BBC Radio 2. "I was like, 'Who am I without Wembley Stadium saying, 'you're awesome'?"
"I'm trying in my life right now to not attach too much to being a pop star. I'm trying not to get my self worth from external validation."
He was speaking as Coldplay unveiled their new single, Higher Power.
They premiered the 80s-inspired pop song on board the International Space Station overnight - teaming up with French astronaut Thomas Pesquet, who beamed the music back to Earth by satellite.