Many nightclubs from this era were very loud and very dark. Plus some of the best ones were incredibly crowded. To begin with, I could seldom get back far enough to get people into frame from head to foot and when I could, people would be constantly walking in front of me all the time. Then I bought a 24-mm lens and only had to be four or five feet away.

I preferred that option, where my camera (and by proxy, me) could look them straight in the eye. The way they reacted to me was always interesting. Sometimes hard young men would reveal vulnerability and a softer side. In the case of teenage girls, I often got a fascinating glimpse of the woman inside.

I started out, in the mid-'70s, taking photographs of rock bands that I liked but not because I really wanted to photograph them. Initially, I was pretending to be a photographer, simply so that I could go up to the front of the crowd and be a bit closer to the bands. But, I found I was gradually developing an interest in the photos I took.

It's more about subtracting every single buck from the tourists that still flock there. Gentrification and the need for developers to maximize their profits from every square inch of the place means that there just aren't any scruffy little basement clubs left. Those scruffy little basement clubs were the areas lifeblood. Now, it's all penthouse flats and global brands. They destroyed the very thing that drew people there in the first place - it's superficial sleaziness.

Things are very different now because a lot of those little clubs don't exist. In Soho for instance, where nearly half my nightlife photographs were taken, it's rapidly changing. There isn't the same after dark frisson of excitement about the place any more.

Once I became a photographer, it stopped me being scared or intimidated by gangs of young men of whatever stripe. Initially, I could hide behind my camera but eventually I came to realize that if I was polite and friendly to them, then they probably would be to me too - a good life lesson.

I went from being an underpaid ad man to quite a successful photographer in a very short time. Success breeds confidence and as soon as I got properly confident, I developed my own style. After that I never looked back.