I'm 56 now, but music still has the same effect on me as when I was 15. Every so often, I'll hear a couple of songs that will just kill me and make me go instantly to my desk to write, and then straight to the piano to compose. That feeling is something that's never gone away and I feel really blessed by that.

I know some people say they used to write better when they were younger, but I feel the greatest writing for me is yet to come. I'm always working on new material and I'm always inspired. At the moment, I'm going between preparing for a short residency at Caesar's Palace in Las Vegas and composing a series of songs based on the books of Rhiannon, these Welsh legends that I really love. They're such beautiful stories. It's what the old Welsh people left behind to teach future generations about how to raise their children and how to deal with relationships—how to run their lives, basically.

Another thing that inspires me in my music at the moment is my niece Jesse. She's 13 but she's an inch taller than me, with black hair and blue eyes. Sometimes when I'm running on my treadmill and listening to music on my CD player, I'll be singing and howling along while Jesse's in the same room and I'll make her listen to how the singer is singing. Jesse was with me when I wrote four songs for the last Fleetwood Mac album, and she even got to sing on the title track, "Say You Will." That was fun.

It's not that I want to push her into music. I would never do that. The arts are not something that you can push on anybody. People either have it or they don't. I really believe that. I would say to girls who are thinking about getting into making music that the most important thing to do is to learn how to play an instrument well. If you're a girl who can play, you can always get a job. You can play keyboards or guitar in a band no problem. Since you're a girl, you're even more special.

But making it all last, you know, having longevity, is another story. The thing that's kept me going all these years is absolutely "the music." It sounds like a cliché, but the music is way more personally motivating than being in a band. Yes, I was in a band, but it's not like Lindsey Buckingham and I wrote songs together. We never did. We were very, very separate in that. He was a very good producer for my music but that was that.

I was very selfish and was not willing to give up my art for a family and a husband. Now, at this point in my life, I am really glad, because I see so many of the people that did get married and did have relationships—they're all divorced, they're all miserable, their children are miserable, and it's like I'm thinking to myself: "You made the right decision."

I guess for me, as a woman, there was nobody who would tolerate my lifestyle. Even the richest of rock stars had reason to be jealous of me. The poorest of people, the waiter, the great men in my life, it hit them all very hard.

There was the waiter. There were the doormats and the security guards with some other famous bands. There were all these really beautiful and sweet men who have been in my life and then there's the rich, famous men, but at some point or another, my life was too much for ALL of them. They started to make demands. Like, "Where are you going? And what do you mean you're coming home from your tour but you're stopping over in England for a month?"

That kind of thing doesn't go over well. The long black limousine drives up the long path to your house to pick you up and your boyfriend is waving goodbye to you. It's never fun to be left. It wouldn't be for me.

I had my chances but I would never marry a rock star either. Because you can never trust them. I know, I have watched them while I was out there. There was an unspoken society, which Christine McVie and I always stayed completely away from. We didn't really ever know what the rest of the boys in our band did, but we knew what boys in other bands did because that gossip got to us. Whatever went on in Fleetwood Mac was kept from us. We didn't wanna know anyway. As a woman who lived in that world of groupies and rock and roll excess, I can understand why the men do what they do. But I don't have to like it.

I swear on my mom's grave (and she's not even dead yet) that Christine and I didn't go out and have one-night stands while we were on tour. We never met someone in a coffee shop and then went back and slept with them, ever. But the guys would. And in the rest of the world it happens all the time and it's not a big deal. It still happens now with all the new rock and roll bands.

Whatever went on—and plenty of things did—I'm just grateful that I've had so many beautiful memories in this life of music. I would say the most memorable day I ever had was when I was 29 and we played the first ever "Day on the Green" concert in San Francisco. It was Peter Frampton headlining. We were on before him. The concert was a tribute to the success of Peter's Frampton Comes Alive album, so the promoter Bill Graham had built a huge fairy tale castle on top of this massive stadium stage. The castle was so gorgeous. It was sparkling and glittering, and it had turrets and stairs that went up on both sides. The turrets had seats, so it had this Rapunzel kind of feeling. This was the beginning of 1976, and at that point Lindsey and I had only done a small tour with Fleetwood Mac, where there were like 5,000 people per show. This audience was 75,000 people!

We had no idea what to expect. When I got there, I saw each of our dressing rooms had personalised, carved-wood signs in beautiful calligraphy with our names written on them. Of course they were just trailers, but oh what trailers they were!

The first performer was this guy named Lee Michaels. I'd lived in San Francisco, where he's from, so I was a fan of his already. I went out and hid on the side of the stage and watched the show, and then I went back and got dressed during the last half of the next act's set. When we finally got on stage to do our set, I just thought to myself: "Where would I ever want to be in the world except for this sparkling castle in front of 75,000 people?"

I was standing in the middle of the stage thinking, "This is the big time!"

Even better than that was that my best friend and I got to go up the stairs on the side of the castle and sit in those little princess chairs and watch Peter Frampton play live. Peter's an amazing guitarist and back then he had that shoulder length golden hair. He was so gorgeous. He looked like a king. So to sit up there and watch him from that vantage point was just wonderful. When the show was over there was a huge party in Frampton's hotel suite. It was just a magnificent rock and roll moment.

At the party, everybody was drunk. But I can remember it like it was yesterday, so that means it was fun. Everybody was drinking wine, and there were wine spritzers there because of all the English people. It was a beautiful thing. At that point the serious drugs hadn't kicked in yet.

So yes, some bad days came later, but there's always been good days too. All of it, the good and the bad, is what allows me to sit now in a house that overlooks the ocean and have complete freedom in my life. I'm just really grateful to music every day.

STEVIE NICKS AS TOLD TO ANDY CAPPER