> your boss is not your friend

I wholeheartedly agree. This is why you should be planning from day 1 on ways to make sure that your career is never dependent on a single individual’s or organization’s whims. They will be doing the same for you if they are smart.

This may sound ugly or cynical, but it’s a fact of life. Discretion is not just about what information you choose to reveal, it’s also about figuring out who is and isn’t “on your side” for the long run. I think we all fail at this at various points in our lives in some way or other.

Your boss is not your friend, but your boss can be your mentor. I've had to form a level of trust with my boss because I really needed his advice as a first time tech lead.

I knew the technology I was implementing pretty well but now knowing how to approach higher ups and people in other departments is just as important.

Let's be clear, though: I'm not her boss. She's two levels below me and not in my direct chain of command, currently. I'd actually be less down on it if I were her boss, and she was speaking just to me, seeking advice or something. There's a sort of "Let's have an open discussion about career stuff" venue in which you kind of agree to suspend judgment.

Just randomly dropping that factoid in a group discussion where it's difficult or impossible for me to probe deeper and understand what's behind it is not a great idea. That makes it easier for someone to take a bad impression from it.

But, also, yeah, I agree, your boss is never fully your friend. I like a lot of the people who work for me, and in other circumstances I think I could be friends with most of them, but part of my job is to evaluate them, including negatively. There is an art to expressing vulnerability in a way that creates intimacy without making a person question your abilities. You can't just assume that everything that you say will have only positive consequences.

And adding on, I try to avoid it, but sometimes you have to tell your boss personal stuff. When I was looking for a house, I had all sorts of short notice appointments. If I didn't let him know, the first thought is that I was interviewing.

Also, I have "cold induced asthma". Whenever I catch a cold, my asthma flairs up and I'm heavily medicated. I had to explain why I spent so much time working from home.

I agree with your points. "Your boss is not your friend" just means that you can't talk to your boss just like you talk to a friend. But it can be easy to mistake one's boss as a friend, and that's where there's a risk of saying things that should not be said.

All your end advice is true, and I recognize the sentiment of "you can never know". Indeed, a date recently asked me if I could read her mind, as happens often, but this time I said I can read her body so basically yes, I can read her mind. I can do this in interviews as well, which is a curse in a slimy rotten marketplace. It's pretty easy to see the next question to ask somebody and corner them if you want. Lack of mental clarity or lack of social exposure or programming can hinder one.