Green Day Are Now Rehearsing 'Kerplunk!'

But what does it all mean?
Green Day Are Now Rehearsing 'Kerplunk!'
Adding to the ever-growing mystery, Green Day are now rehearsing another one of the band's classic albums. This time, it's their 1991 record Kerplunk! 

Drummer Tre Cool took to his Instagram the other night to reveal the news, posting the following:
 


Of course, this comes in the wake of Green Day first recently rehearsing their beloved album Dookie and then shortly after doing the same for their follow-up album, 1995's Insomniac.

While this has led to all sorts of fan theories, including anniversary tours, Green Day have yet to let fans know what these rehearsals are really all about. After all, they could just be the band taking a simple trip down memory lane.