When you share a YouTube video using the share button it adds “si=some_unique_code” to the URL. If you don’t remove that it shows your personal account to anyone who receives it so that they can chat directly with you. For a lot of people this is their real name.
I’ve seen it all over Lemmy so I figured I’d mention it here! You only need the stuff before the question mark in the URL to let others see the video.
This can also be turned off in your YouTube settings under the privacy section. The setting is “channel visibility for shared links”. It will still add the si code for tracking though.
Sample the people around you in real life. They don’t know any better, regardless of age. The group that experienced it has already largely forgotten it because the link purpose got obfuscated and the need became obsolete in everyday use