There's nothing better than just staring at a buttercup, struggling to make an impact on the world.

I was a solicitor once, so I'm truly grateful because I know what it's like to have a proper job.

I worked in a chicken factory, in a steel foundry, I worked on the bins for a year or so. It started as a summer job, but I stayed on because I liked it very much. I liked it that it made you very fit, doing all the lifting and that, so I could wear short-sleeved t-shirts, which I'd never been able to do before!

I used to like getting cups and putting tiny bits of food and liquids in them. I'd grow mould plumes in the dark wardrobe of my little back bedroom. Not to eat them, mind - just to admire the growing power.

But man has still another powerful resource: natural science with its strictly objective methods.

The thing that upsets me is the ubiquitous use of reward technology, which uses our evolutionary biology against us.

It's very clear to users, more clear than in other apps, that Foursquare is an app for search and discovery, and we're very good at delivering you a social map that will show you friends' faces on the map and things that you might like.

Many have gone on to do important scientific work but all remember those wonderful times when we and our science were young and our excitement in meeting new challenges knew no bounds.