Bursting on the scene at the ripe old age of seven thanks to her scene-stealing role in ET: The Extraterrestrial, Drew Barrymore experienced international fame at an age when most people were still learning to tie their shoes, and she’s been very open about how living in the Hollywood fast lane at such a young age nearly destroyed her.

“I had the weirdest life ever,” admits Drew in a new PEOPLE cover story, looking back on becoming a hard-drinking boozer before entering puberty, going to rehab at 12 and ultimately living on her own at 15.

Related: Drew Barrymore Shoots Down Rumours On “E.T.’ Sequel

Yet it’s the “in-between moments” of her wild life that she celebrates in her new memoir, Wildflower.

“I’m certainly not known for being boring,” she tells PEOPLE. “But I also think things that are emotional and raw are also a lot lighter than they seemed. Someone once said to me, ‘But your life… it’s so sad.’ And I was like, ‘Well, no, it’s not to me, but I could see how you would think that.’ My life is amazing.”

Drew reveals that she wrote the book for her daughters, three-year-old Olive and 18-month-old Frankie. “When I first started having children, people were like, ‘Well, what are you going to gell them about [your upbrining]? And there was always a connotation and insinuation of, ‘You should be ashamed.’ But that’s crazy. [My daughters] are going to know I’m not some holier-than-thou person who just doesn’t want them to live. I just want to guide them in the best way possible.”

Related: Drew Barrymore Embraces Her Shape: “I Don’t Have A Bikini Body

In addition, Drew also reveals that she experienced postpartum depression after having her second child, admitting it threw her for a loop.

“I didn’t have postpartum the first time so I didn’t understand it because I was like, ‘I feel great!’ The second time, I was like, ‘Oh, whoa, I see what people talk about now. I understand,’ ” she says. “It’s a different type of overwhelming overwhelming with the second. I really got under the cloud.”

You can read more of Drew Barrymore’s interview in the new issue of PEOPLE, on newsstands Friday.