Do you agree on 'Your biggest supporter is a stranger'?

Recently I read this article:

Junior Developers Checklist for Landing a Remote Job

Carl-W May 19 8 min read

#remote #webdev #beginners #career

and came across a thoughtful comment:

Robert Marshall

May 20

'Your biggest supporter is a stranger' - how true that is!

I decided the topic might deserve to get extended a bit.

Many believe, that Rule number #1 is not to reveal your future plans to anyone, as they might want to secretly dismantle them by stalking you on your code-related online presence, creating a bad rep for you on your projects feedback, putting a pressure on you by irritating you in daily communication, etc..

Have you ever experienced someone from your closest network to stay in your way to success? If so, could you re-call some examples from real life and what were the reasons (you were aware of)? Jealously? Competition?

Ultimately, is it true, your biggest career opportunities came from complete strangers and your closest network wasn't involved to find them?