Giving up the innovative, we-can-change-the-world culture of Google (GOOG) is hardly an easy decision for any executive who works there. But for Sukhinder Singh Cassidy, who announced this morning that she’s leaving Google to rejoin the world of start-ups, the decision was a natural.

“My father drummed into me that I should work for myself,” says Singh Cassidy, 39, who is Google’s president for Asia-Pacific & Latin American operations until she moves to Accel Partners, the Silicon Valley venture capital firm, as CEO-in-Residence next week. “My father always told me, ‘You want to control your destiny.’”

In a company of innovators and iconoclasts, Singh Cassidy has long been one of Google’s most adventurous and global-minded executives. Born in Tanzania and raised by doctor parents–her late father was from Uganda and her mother, still a practicing gynecologist, is from India–Singh Cassidy grew up in Canada and has spent her adult life refusing to be pigeon-holed or tied down. After college at the University of Western Ontario, she took the foreign service exam and the LSATs, thinking of going to law school or maybe medical school. She took an altogether different route, joining Merrill Lynch (BAC) and working in investment banking in New York and London for two years.

“I’ve always been entrepreneurial at heart,” she says. So she moved into tech via stints at Amazon.com (AMZN), OpenTV and BSkyB, the News Corp.-owned (NWS) British pay-TV provider. In 1999, she co-founded Yodlee, a financial-services Internet company, and headed business development there until moving to Google in 2003.

[Read on at Fortune.com]