Your main point was about salary negotiation (and I don't know much about that) but your example about interviewing is interesting to me:
> I spent a full day interview [...] and yet I thanked every single interviewer for their time, and told them how much I appreciate [...]
Where I work we became very sceptic about this trait in candidates, especially if someone is overdoing it. Then the suspicion rises whether they are overcomensating for another trait they believe about themselves.
I feel that being likable is table stakes and not something you would optimize for that much.
> Where I work we became very sceptic about this trait in candidates, especially if someone is overdoing it. Then the suspicion rises whether they are overcomensating for another trait they believe about themselves.
I'm also skeptical about overly positive candidates, but if their other visible traits are average, then there's no need for me to be paranoid.
The odds that there's a problem with them that I cannot determine during the interview is exactly the same as the odds for any other candidate.
Being that the odds are the same, I may as well get the person who everyone wants to work with.
> I spent a full day interview [...] and yet I thanked every single interviewer for their time, and told them how much I appreciate [...]
Where I work we became very sceptic about this trait in candidates, especially if someone is overdoing it. Then the suspicion rises whether they are overcomensating for another trait they believe about themselves.
I feel that being likable is table stakes and not something you would optimize for that much.