Strangely, from a life-change standpoint, I sold the company I was running and got divorced in the same month. And so there I was, at home, and I'm not the CEO. I took a few months thinking about what I wanted to do. When the first call came in about running a company owned by Deutsche Telekom, I thought it was laughable and really not something I'd do. I took the meeting mainly because the headhunter I knew. At first I thought I was just helping her fill out the roster, but then I dug into it.

If you go back in my career, you'll find I've always been a lead-from-the-front people-manager guy. I've always been outspoken. I've always attempted to break the mold. My advice to myself, then, would be to go all in on it. The world doesn't need another cookie-cutter business-school leader. The world needs somebody to stick out and be loud and proud.

When I used to live in Asia, they used to say, "If you're going to sing karaoke, you want to go after the worst singer." And I'd be coming in Deutsche Telekom after the worst singer.

Deutsche Telekom was a brand that people still loved, the nerds loved it, and it was still there, it was still visible. The advertiser was OK. But it was a mess. It was in my mind, though, intuitively obvious what to do. I had some advisers and friends, and we looked at it and said all you have to do is get the iPhone, buy some spectrum, consolidate the industry, reinvigorate the brand, and take this company public.

Part of my role at T-Mobile is the ability to just be myself, because I'm 58 years old and I've done very well, and I don't need to fight my way up the hierarchy with my suit and hair anymore.

When I finished my last job, at Global Crossing, it was the first time in God knows how many years that I wasn't in a job. It was probably 32 years or so, and there I was, it was like pow!

It's kind of fun at my age to go back and talk to business-school people. I tell them, "I can summarize everything you need to know to lead a major corporation. Are you prepared to write this down?" And then they get all ready. I tell them I can summarize how I succeed as a leader: Listen to your employees, listen to your customers, shut the f - - up, and do what they tell you.