Cold messages to people in my field, do they work? (San Diego)

I want to talk to people in a new field but I hate cold messages. I have read a lot of threads here and could not find my exact situation. Some people reply with short answers. What did you ask?

I asked what they wish they had known at my stage. People enjoy answering that.

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