The title may come off as a bit dramatic, so I’ll clarify what I mean. It’s impossible always to be professional. We have our personal lives and downtime. You shouldn’t keep up a business persona during all occasions. That sounds exhausting. What I am saying is to consider how you are perceived at three crucial points during your time with a company and the importance of being considered as consistently “professional.” Be mindful of the impression you make while interviewing for a company, while you are working for them, and when you leave. So, when we look at it this way, yes, always behave like a professional when dealing with potential, current, or former colleagues.