permissions to use names from 13 yrs ago

Sat Nam! (literally "Truth Name"--a Sikh greeting)

Options:
You can sometimes leave the name out and reference something else about the person. (ie my first doctor)

You can give the person a fake name.

If the person is dead, it doesn't matter.

If the first name is generic (ie John), you can just use that. Ditto with last names.

That said, if what you're saying about them is essentially positive, then it's acceptable to use the name without permission.

But...If you can track the person down and get the person's permission, do so. Wonderful things have happened when I've done that.

Blessings,

Siri Kirpal

Sat Nam! (literally "Truth Name"--a Sikh greeting)

Most people will be grateful and delighted that you remember them with fondness.

Blessings,

Siri Kirpal

For those you can't track down, the issue solves itself (IMHO):

If they're famous enough that their given name matters, you are likely dealing with a celebrity and can thus write about them as long as you aren't slandering them.

For the rest of your "characters," a name is simply a way the reader keeps track of them. Pick something that personifies the character and stick with it. As Juliet said, "A rose by any other name...."

If you had to have permission to use names, I doubt there would be an autobiography, a biography, or a memoir on any bookshelf, anywhere.

I can write about my life, and all the people who have been in it, without anyone's permission, celebrity or not, good, bad, or indifferent.