Chimps are very quick to have a sudden fight or aggressive episode, but they're equally as good at reconciliation.
What you do makes a difference, and you have to decide what kind of difference you want to make.
I had been told from school onwards that the best definition of a human being was man the tool-maker - yet I had just watched a chimp tool-maker in action. I remember that day as vividly as if it was yesterday.
I think the most important thing is to keep active and to hope that your mind stays active.
It was because the chimps are so eye-catching, so like us and teach us so much that my work was recognised worldwide.
I'm always pushing for human responsibility. Given that chimpanzees and many other animals are sentient and sapient, then we should treat them with respect.