My earliest memory of my dad was when I was six years old. He’d just been released from captivity in Vietnam and my mom had rented a beach house for the three of us to stay in. I couldn’t figure out exactly who he was, because I had no memory of him – I was only nine months old when he was taken prisoner.

Being the youngest in the family, with two older brothers, I was very spoiled, but when my dad came back he was very strict and that was shocking to me. But he was also very loving. We lived in Florida and he taught me how to bodysurf, which he’d do with both hands behind his back because of his injuries from Vietnam. We’d be woken up in what felt like the middle of the night to go crabbing. My greatest memories are with my dad in the ocean.

I definitely inherited from him a wanderlust, and we bonded over music, but politically we didn’t see eye to eye. I’m very liberal, very much a Democrat, although I did support him 100% when he was campaigning. He respected that I had different opinions. I think he thought I’d grow out of it, but I got even more liberal. But it didn’t matter: there were more exciting things to talk about, like baseball – we were both baseball fanatics.

He always wanted to be in politics, he always wanted to serve and he did a great job as a congressman and later as a senator. I was very proud of that. But I also kept it very quiet. I didn’t announce that John McCain was my dad because I was building my own life and career.

When he ran for president the first time, I was working with the White Stripes as a music publicist. Saturday Night Live booked my dad to host a show for which I’d already secured the White Stripes as the music act. I was like: “Dad, I’m going to bring Jack and Meg over to your green room because you definitely don’t want to go to theirs, because everybody’s smoking and drinking.” He was like: “No, no, I’ll come to theirs” – and he fitted into that smoky green room just as well as he’d fit into a high society dinner.

John McCain with his eldest daughter, Sidney, in 2017: ‘His energy left me in awe’. Photograph: Sidney McCain

He had an incredible amount of energy. On the campaign trail, he lived on terrible food – hotdogs and doughnuts – but he’d still be charging forward to the next event. I hiked the Grand Canyon with him and when we stopped for the night I’d want to sit down for just a minute and cool off – but no, we had to get the tents up straight away. His energy left me in awe.

As a politician, he was very independent-minded. He didn’t care whether you were Democrat or Republican – he cared if you were a person of quality. Partisanship in American politics really concerned him. He used to meet with Obama once a week when Obama was in office. I’m sure they didn’t always get along, that some heavy discussions were had, but it was always done with respect. Which is all too rare these days.

He didn’t think he was going to die. He was forever hopeful. When he was diagnosed with cancer, he told me: “I’m not dying. I’m just not dying.” I said: “OK, Dad, you’re not dying, we all believe that you’re not going to die.” But he did. He didn’t have a choice in the matter. But I’m positive he made peace with himself and with everyone around him.

He was an incredible politician and one of the finest men and I really hope that we see his like again. In confusing times, he tried to be a beacon of what is right and I think he will be remembered for that. I’ll miss him. I think the world is a much sadder place without him.