How many Internet users really know what it means when there's a little golden padlock in the URL bar? What goes through their minds when there are security war

How many Internet users really know what it means when there's a little golden padlock in the URL bar? What goes through their minds when there are security warnings about not having the golden padlock? I knew a guy who wouldn't open my email to him, because the icon/avvie was a question mark or something, and so it must be malware. He pointed it out to me in person. Now there is a social-medial industry standard 'blue check' or 'verified account'. Instead of a golden padlock meaning the same, narrow thing, everywhere and always, the blue checks are implemented however they want. You can put a blue check in your Slack status if you feel like it. So what does a blue check mean?