Overview
The person who's just asked you if you can keep a secret? Tell them -- honestly -- that if it were your secret, you'd have to refuse, but since it's theirs, it's a given that you'll take it to your grave. There's no way you'll allow it to be even tortured out of you. So sit down, listen to their story and offer any advice you possibly can. With the array of experiences you've had throughout life, you know you can help. They've definitely found the right person.