Cold messages to people in my field, do they work? after 12 years as a bank teller

A friend suggested informational chats and I do not know how to ask. I worked as a bank teller before this. Some people reply with short answers. What did you ask?

Do not apologise for asking. Most people remember someone who helped them.

I wrote three short lines: who I am, why them and a small ask for fifteen minutes. About one in four said yes.