I hate it when you see in films people with their anoraks flapping open in a blizzard. They'd be dead in a couple of minutes. It's got to be real. It's got to work.

It's sad that you don't see drivers being real people.

I've climbed Stromboli when it's erupting, which is quite a heavy climb: three hours with a helmet to get to the top. When you're there, and it's dark, and you can see this eruption and feel it, it's quite different to watching it on TV.

You will remain where you are...,until you change your mindset.

For a novelist, the great thing about the Stone Age people is that we know virtually nothing about their beliefs - which means that I get to make it up! But it's still got to be plausible.

You dread that there will be real problems during filming.