Why she started a business at 18: I didn't have the grades for college, and I didn't want to do nothing while my friends were at school, and I could never find the matte lipsticks I loved, so I decided to make them myself.
Why she was taken seriously as a young entrepreneur: I don't think any prejudice—whether it's about age, gender, race, appearance—stands a chance against strong research and a clear articulation of what you want to do.
Her biggest business mistake: A few years after I started my first company, I let my partners convince me to do a full line of color cosmetics.
What she learned: To trust my instinct. My partners had a rational argument—we'll make more money if we sell more than just lipstick. But I wasn't passionate about the other products. Within four years, we went out of business.
When the failure hit her: I went to see a therapist months later—I'd moved to New York, started a corporate job, had no friends, and everyone else in New York seemed to go to a therapist. When she asked how I felt about closing my company, I said, "Really relieved." But I was bawling my eyes out. I can remember saying, "I don't know why I'm crying." I had never mourned the end of my business.
Why she went back into business: I started writing this book and was thinking about the early days of my first company, and I started feeling like, "Oh God, I think I want to do this again."
The (nonlipstick) beauty products she packed for her recent book tour: My Shu Uemura eyelash curler, to make me look awake; Darphin Soleil Plaisir SPF 30 sunscreen, to protect my skin; Frédéric Fekkai Glossing Cream, to attempt to control my naturally curly hair; and a lot of green tea, to energize me.