Before I went to my first professional conference my mentor sat me down and said, "From here on out - every single interaction you have, particularly with new people - until you get tenure if you get tenure - is a job interview."
It was and remains absolutely great advice to keep in mind that all interactions can have an impact on your career until you arrive at a protected place. And if you want to get that protection and keep that protection you'll act in a professional manner.
Which is why one of my pet peeves in the workplace is when ostensible established professionals try to play "gotcha games" with other people and find ways to "teach the youngins a lesson". Everyone has it hard enough trying to do their job and conform to ever changing standards for people to also be assholes and try to catch them acting in unprofessional ways. Which is why I try very hard to always be professional and I hold others to those standards.
Only twice in my career has someone called me unprofessional and in both cases they were steadfastly wrong and realized it quickly. Although only once did I get an apology, the other person is still carrying a grudge about it.
It's important to know the law protecting people in this way was not passed until 2011.