Katherine Zaleski was once a cynical twenty-something who saw working mothers as an obstacle in her business decisions: she found herself silently judging them and avoiding making deals with them. Now, her view on the matter has completely changed, because she’s just had a child of her own.

“I didn’t realize how horrible I’d been — until I had a child of my own,” Zaleski admits in a Fortune piece she wrote recently, apologizing to working mothers for her younger self. “For mothers in the workplace, it’s death by a thousand cuts — and sometimes it’s other women holding the knives.”

Zaleski, who was a former manager at The Huffington Post and the Washington Post, is now CEO and president of her own company called PowerToFly, which aims to help working mothers work from home.

At the time, it was easy for her to judge women who skipped happy hours, scheduled later meetings, or wanted to work from home for the sake of their children. But it wasn’t until now that she was fully able to empathize with their plight. Working mothers are often forced, unfairly, to choose between career and kids — and Zaleski realized she didn’t want to do either, but rather find a balance. This is what motivated PowerToFly.

Ultimately, it’s the working moms of the world who are masters at getting things done.

“I wish I had known five years ago, as a young, childless manager, that mothers are the people you need on your team,” Zaleski writes in her article. “There’s a saying that ‘if you want something done then ask a busy person to do it.’ That’s exactly why I like working with mothers now.”