You shouldn't assume that everyone is as generous as you have made your pretend writer.
True, but we're talking about life-long friends, here. What you you suppose they talked about, baseball?
It certainly could turn into an imposition, if you're basically asking a friend to act as an unpaid editor, agent and mentor. But if you keep it light and friendly, if you offer as much as you ask for, great things can come of that kind of lunchtime chat. I would love to be a fly on the wall when Spielberg and Lucas get together for a beer.