When I go to T-Mobile retail stores, I jokingly tell the employees that everybody between me and them is the enemy. In effect, what I mean is that in my paramilitary hierarchy, if I can hear them and they can hear me, everything will be fine. All we need to do is make sure the entire company understands that it's their job to pass information between us. And so far so good.

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.

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'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 think this job at T-Mobile has more than anything else helped me really see and understand how to set a strategy, communicate like crazy, and then passionately lead from the front of it.

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.

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.