We meet people in our careers. As time progresses, these relationships develop, and we stay in touch. We (mostly) subconsciously organize these based on expertise or employer. We remember what folks do and can be reluctant to update that view.
It is easy to forget that as we work on ourselves, develop in our interests, and pursue new ways of being, the people around us do the same. If we're not thinking, we might push against others' change.