There is a set of railings, about six or eight of them, just before the entrance to the Place de la Concorde, about a kilometre from the Tour de France finish on the Champs-Élysées. I stood on those railings with my brother and my mum on 25 July 1993 watching the Tour de France go past.

It all went by in a flash, but I spotted Miguel Indurain in the yellow jersey – about to win his third Tour in a row – and Gianni Bugno in the rainbow jersey of world champion.

It was my first sight of the Tour. We'd come over from London for the weekend, gone up the Eiffel Tower the day before, then watched the Tour come into town on the Sunday. I remember thinking how big it was, how huge it was, seeing the riders whizzing past. I never imagined that 19 years later I'd be coming down there in the same position as Indurain.

It sounds cliched, but it's the stuff of childhood dreams really. It's what I've dreamed of for 20 years but I never dreamed it could become reality.

A lot of riding up the Champs-Élysées is goose-pimple stuff. When you come on there the roar, even when you finish last in the Tour, is the same for everyone. But coming on in the yellow jersey surrounded by the guys who have put me there, with all my family there waiting for me – Well, I won't swear but …

It's very difficult to sum up what I'm feeling in words. The thing that's struck me most over the last 12 hours or so is just what it means to other people around me, like my personal photographer breaking down in tears in my room, and my mechanic in tears as well: you just think hell, it's not just me who's gone through this, everyone else around me has lived it too.

That's quite a nice feeling, that you can have that impact on someone. So I'm almost the last person to soak it up and know what it feels like. And I guess that will happen over time. A lot of it is relief. It's a little bit like when I won the Olympics for the first time in 2004.

It's almost a kind of disbelief that this is happening; it's little things like seeing the front page of L'Équipe, with my picture on it in the yellow jersey. You don't realise it's you on there. It's strange. And there are messages like the one I had from Sir Chris Hoy: it's humbling to hear praise of that kind. The biggest accolade is respect from your peers. They are people I look up to. so it blows you away a bit. In the medium-term, I want to go on until the end of the season, at this stage I want to keep going. My job is to ride a bike and that's what I like doing: going out on my bike, and training.

In the short term, it's gold or nothing in London now, if I'm 100% honest. We have prepared for this for a long time. We always knew I would be chasing the win in the Tour, and that after that I would be going for the win in the time trial in the London Olympics, so we planned for this happening, although we weren't taking it for granted by any means. Everything is in place for the next goal.

I've just a done a world-class time trial, on Saturday, averaging a ridiculous amount of power after three weeks of bike racing and two really tough Pyrenees stages, a 222km stage on the Friday at a 44km per hour average speed with a lead-out in the finale, and then I still did that on Saturday.

I was already thinking about the Olympics on Saturday. It's realistic to think I can win that now. I've made so many improvements in my time trialling this year. A year ago when I was beaten by Tony Martin at the worlds [the UCI Road World Championships] by 1 minute 15 seconds, I thought I was probably just going to get a medal. But I've certainly closed the gap now, if not gone past him. It's going to be another tough race but a very realistic chance of gold. So physically, you'd think not a lot's going to change in nine days. If anything, I'm going to be fresher. And once you start thinking in those terms, that you're so fit and you've trained for the demands of the three weeks and you've actually got three days off in between the road race and the time trial, it shouldn't be a problem. I will do the road race, but I don't envisage anything other than working 100% for Mark Cavendish.

An Olympic athlete can't envisage doing the Tour de France 10 days before the biggest race of their life, a marathon or whatever, but racing is what we do as professional cyclists, and we do so many races during the year that actually having nine days off amounts to a holiday. Physically, nothing changes – if I did that time trial yesterday in nine days' time, I'm going to be in the ball park.

That's why I flew out of Paris on Sunday night to a secret location, so I can get on with riding my bike for the next couple of days, in peace and quiet with no motorbikes around me taking photographs and getting in the way. Coming off the back of this, it will kind of add the hundreds and thousands on the cake. You could say the icing is on it. We've just got to put the little cherry on top.

I've set a precedent now for performances. I can't sit and say I'll be happy with a silver, or happy with a bronze. It's got to be gold now.