For Nicola Sturgeon, 2015 has been quite a time. “A phenomenal year. But then last year, with the referendum, was also a phenomenal year. I’ve had two, two-and-a-half years of being absolutely, constantly on the go at 150 miles an hour.”

She is, she admits, a wee bit tired. Which is not surprising. She was the breakout star of the general election leadership debates. The new villainess of the Daily Mail, which splashed her on the front page with: “Is This the Most Dangerous Woman in Britain?” The Sun photoshopped her face on to Miley Cyrus’s body and called her party the Tartan Barmy, but there was no stopping her.

The SNP won 56 out of 59 seats in the general election and Sturgeon, smiling, unflappable, immaculately turned out in a series of trim suits, posing with voters for a stream of selfies, became the frontwoman for a new force in British politics. Did she foresee any of this in January? “I was really optimistic because all the signs were that the SNP was going to do really well, but I’m naturally quite a cautious person and there was a large part of me saying it might not work out like that.”

She had been through the referendum campaign, yet the media attention came as something of a shock. “I hadn’t anticipated how much scrutiny I would end up under. It wasn’t until the first leader’s debate that I really started to focus on that.” It became quite stressful quite quickly.

“I kept reading in the papers how David Cameron and Ed Miliband were doing these big role-playing exercises, whereas I prepare for these things more like I’m swotting for an exam. It was very intense and nerve-wracking. I was very nervous. Probably more nervous than I’ve been for anything else in politics. Before we went on air, we all came together for the first time and you could tell the others were really nervous as well. Strangely, that calmed me down.”

What did she make of that Mail headline the next day? The most dangerous woman in Britain? “I loved that. It’s the nicest thing the Daily Mail has said about me. I still trade off it. It did my street cred no end of good. I owe the Daily Mail big time for that.”

As the election drew closer, it became clearer that the SNP was riding high in the polls. “But I still had that uncertainty about how many seats we would win. Some of the MPs that were defeated by us were big names that had been in politics for a long time and you couldn’t imagine defeating them. You might think, we’ll win that seat and that seat, but we’re not going to beat Douglas Alexander.”

Election night was “totally frenzied” and “a bit of a blur”. And while she was euphoric at the result, “there was also that sense of, ‘Oh my goodness, this is a massive responsibility.’”

The nearest comparison is probably the 97 Blair election, isn’t it, I say. And the Blair years didn’t end so well… “No, but I’m not intending to illegally invade another country any time soon.”

In the election’s runup and immediate aftermath, there was what can only be described as Sturgeon-mania. And not only in Britain. After the result, she went to the US, touring talk shows and news programmes. “It was hard work. But I hadn’t anticipated how interested people would be before I went. That came as a wee bit of a surprise.”

Watch video of Jon Stewart’s Daily Show interview with Nicola Sturgeon

Her No 1 hit on YouTube now, though, isn’t the leadership debates, it’s her appearance on the Daily Show with Jon Stewart. What was that like? “Terrifying. I was going to the States and the invitation had come and it’d been put to me weeks in advance and I said, ‘Yeah, of course.’ Then, 24 hours before, I was like, ‘I can’t believe I’m doing this. This could be an absolute career-ending humiliation.’ But I think I got away with it.”

Then, at the end of the summer, she saw the 56 new Westminster MPs off to parliament. Was that a bit like waving off your children to boarding school?

“A wee bit, yes. I was there when they were all arriving. But leaving them there was a bit of a wrench. It’s been something we’ve had to adapt to because we’re not used to having this big group of MPs in Westminster.”

There have been so many highs for Sturgeon this year. The leader debates, the election, meeting Christine Lagarde of the IMF and Martina Navratilova, heroes both. Appearing in Vogue. Could she have imagined that five years ago?

“I think most people would have laughed at that. The whole Vogue thing, I suppose I’m slightly conflicted about. I do complain about the focus on women politicians and what they wear and how they look. But getting the opportunity to do something like Vogue, it means you can talk to a different audience than you would otherwise.”

It was a year of far more highs than lows, but the death of Charles Kennedy came as a shock to everyone in Scottish politics. “I was desperately upset. I didn’t know Charles very, very well, but I’d known him for a long time. I spent a fantastic couple of weeks about 20 years ago in Australia with him. We were on a political exchange and I got to know him pretty well. It’s tragic. Charlie was one of those people that was genuinely liked across the entire political spectrum.”

Did it put it into context for you? The human cost of politics? “I’d just come from a meeting of the Westminster group and I’d been thinking about that. Lots of our group are relatively young. That kind of stuff was on my mind when I heard the news about Charles and it is a reminder that there is quite a lot of personal sacrifice that comes with being a politician. I do sometimes struggle to wonder why we do it. Rejection for people is really tough.”

Sturgeon took a “working holiday” of a few days in Portugal in the summer, ie, not a holiday at all, and says there might be “a bit of a lull” on Christmas Day and Boxing Day. “Then it’s going to be pretty non stop.” The Scottish parliamentary elections are in May. And off she goes again… campaigning, knocking on doors, preparing for a new volley of selfies.

How many selfies have you been in this year? “It will be in the hundreds of thousands, I think. I know how every make of phone works. It really deeply troubles me when I come across a phone I don’t know how to work in selfie mode. At night, very, very often the sorest part of my body is my cheekbones.”