I started TOMS at 29. Sold it at 43. Fell into the deepest depression of my life at 44. And I'm 49 now. Here are the lessons I wish I'd learned:

In 2006, I had $3,000, no investors, and zero experience making shoes. People said my idea would bankrupt me. Today, it's worth $600 million.

I once heard that happiness comes down to just three things. Simple. Almost too simple. But the older I get, the more true it feels.

I built TOMS, sold it, had the money, the success, the family, and I still felt completely empty. Here are four things I learned about not feeling enough:

When I sold TOMS, everything looked perfect from the outside. I was traveling the world. I had the money, the status, the family. But inside, I felt completely empty. That experience taught me some hard truths:

#2: You can have everything and still feel broken. When I sold TOMS, I had the money, the freedom everyone dreams about. Six months later, I couldn't get out of bed. I was planning to end my life.

Success isn't the same thing as being okay. Your mental health deserves the same attention as your goals.

We gave away 100 million pairs of shoes. And I still felt empty. Because I was tying my worth to what I achieved. And no amount of success can fill that void. Feeling enough starts on the inside, not on a résumé.

#1: Doing more won't make you feel enough. At 29, I thought achievement was the answer. If I just helped more people, gave away more shoes, made a bigger impact, then I'd finally feel worthy.

I spent seven years in depression trying almost everything possible under the sun. And I realized one thing: there is no magic pill. And almost no one is talking about it.

When I fell into a deep depression after selling TOMS, I tried everything you can imagine, and along the way, I learned some big misconceptions about healing.

The three keys to happiness are: 1. Having someone to love 2. Having something to work on 3. Having something to look forward to

I think of these like the three legs of a stool. If one leg is missing—or ignored—the whole thing wobbles.

4. Your body feels the truth before your mind admits it. The stress. The anxiety. The exhaustion. My body saw the crash coming long before I did.

I was in Argentina when I saw kids running barefoot on dirt roads. Their feet were covered in cuts and sores. The problem was simple: they didn't have shoes. I came back to LA and couldn't stop thinking about them.

So I wrote down one idea in my journal: "For every pair of shoes we sell, we give one away." That was it. One for One. The entire business model in one sentence. And that's when the pushback started.