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.

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.

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.

I'm very careful, especially with the company, to not spend too much time playing the success reel because I really do believe that everything that's been accomplished can be parlayed in an equal amount going forward.

I visit T-Mobile call centers. We've got about 18 major call centers in the US, and before I was CEO, I heard that no CEO had gone to physically visit them. I go in, they meet me outside, we take selfies as I stand like a piece of furniture, I tell them about how things are going - but most importantly, I say thank you and help them see that their behavior and their work has driven the culture of the company that's changed the industry and the whole world. It's a bit of a love affair.

I went, and my first interview was with René Obermann, who was the CEO of Deutsche Telekom at the time - wonderful guy. And right after hello, I told him that it was my opinion that he could only fail one way in the US. I said, "Do exactly what you're doing - nothing."

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.