The 28-year-old singer admits in-fighting including the public criticisms and accusations of being controlling she faced on the departures of guitarist Josh Farro, her ex-boyfriend, and his brother, drummer Zac - who has since rejoined - in 2010 and bassist Jeremy Davis leaving two years ago and launching a lawsuit against her and guitarist Taylor York left her feeling drained and seeking a fresh start.
She admitted: ''Two years ago I asked Taylor if we could start a new band. I was so sick of this c**p. I said we should just try something new, give it a new name.''
Taylor added: ''I've wanted to quit this band so many times. Going through all this conflict and drama over the years ... I was just like, 'Man, I feel like we can keep going, but this is not worth it if we don't want to be here.' ''
And the pair are unsure as to why they have continued.
Hayley told the Guardian newspaper: ''Honestly, I don't know. We, for some reason, kept showing up and kept writing and, little by little, the songs got better and we got a little more inspired to do it.''
When Jeremy quit and sued for unpaid royalties, arguing the trio had agreed to share authorship of all the tracks on their 2014 self-titled album, but he had just one credit, Taylor admitted he was too ''numb'' to care.
He said: ''I was just numb. It was just another drama and another example of being in a band and it being really difficult, and feeling bad about that. We have the coolest job ever but why does it have to be so hard?''
And while they are not allowed to address his departure directly, Hayley maintains the lawsuit is ''bulls**t''.
She said: ''What I will say is that it's such bulls**t that we're in a lawsuit. I wasn't OK for a while; maybe I'm still not.''
From 'Happy' to 'Banana Pancakes', these are soaked in positivity.