I also think there is a difference between a private seller and a dealer.

Dealers often have just enough knowledge to make stupid mistakes and to believe their own bullshit. They are used to being perceived as knowing more than they actually do. And they don't like it when they are caught out.

Private sellers are often more open to learning when they run across someone who is polite but appears to know more about that thing they own than they do.

I could be wrong but I think 30 years of professional selling has taught me a little about human nature.

The world cries out for such: he is needed & needed badly- the man who can carry a message to Garcia