What I learned in Guinea is that we are all responsible for the state of our world. The world - and the system by which we trade, share, cooperate and conflict - is clearly not working. We are only as strong as our weakest members. UNICEF is run at every level by strong, relentlessly energetic, deeply capable people who use that strength, energy and capability to help those who need it most: the weakest, most disadvantaged women and children of our world. All I can do now is help make people aware of what is happening, of what they are doing. That is all that I can do. For now.

My father and I used to tussle about me becoming an actor. He's from strong, Presbyterian Scottish working-class stock, and he used to sit me down and say, 'You know, 99 percent of actors are out of work. You've been educated, so why do you want to spend your life pretending to be someone else when you could be your own man?'

Make love, not war. Unless you’re Loki, in which case: do what you want.

I think there's a part of all of us that wonders how we would survive on an island untouched by Man. Even better, an island untouched by Man and inhabited by King Kong.

Loki in 'Thor' is the most incredible springboard into a sort of excavation of the darker aspects of human nature. So that was thrilling, coming back knowing that I'd built the boat and now I could set sail into choppier waters.

I am no saviour. I’m absolutely the last person on the planet who can practically help. I don’t know how to make the different types of therapeutic feeding milk. I’m no chemist. I’m no doctor. I’m no engineer. I can’t manufacture polio vaccines or organise their transportation to the health centres in Saramoussayah or Bissikirima. I can’t build schools, or design drainage systems. I can’t provide the women and children of Mandiana with water.All I can do now is help make people aware of what is happening, of what they are doing. That is all that I can do. For now.

One of the great flaws that we all share is that we think everyone else is cooler, everyone else is sexier; everyone else has all the answers. That was me too.