You say what you want to say when you don't care who's listening. If you're grasping to get your own voice, you're making a strained attempt to talk, so it's a matter of just listening to yourself as you sound when you're talking about something that's intensely important to you.
I'm a global ambassador for the World Wildlife Fund and United for Wildlife and I am also a Unicef UK ambassador. It's important to me to support charities. I never want to take my wealth for granted.