By now, fans of The Big Bang Theory have seen the season premiere photos that show Kaley Cuoco’s new ‘do will factor into the storyline on the CBS comedy—that’s right, Penny will be sporting a pixie cut when the show returns. But for those of you wondering why, EW has a new behind-the-scenes video where Cuoco reveals the catalyst for her extreme makeover. Plus: The rest of the cast shares what they’ve been up to all summer: