"I'm so proud of you!"
As a professor, I have happily had many occasions to speak and think these words. Whenever one of my students, or former students, does something momentous, or accomplishes an ambition, or makes their mark, I feel it, and I get to say it. This is one of the many wonderful features of being in a role of mentorship, guidance, and support as part of one's career.
I've often wondered, though, is this feeling of pride one that necessarily only attaches (at least without condescension) to persons who had at some point been under your supervision? Your students, or your subordinates, or your children?
On many occasions, I have thought "I'm so proud of you" regarding persons who had never been in that role -- had always been a peer. Classmates, friends, or colleagues. It is a happy thought, and so I want to share it. But I do worry about whether it implies condescension. So I ask "can I say I'm proud of you?" or "would it be weird for me to be proud of you?" And they usually reply yes and no, respectively, and so I say it. But I still wonder -- am I mistaken in the feeling? Or am I wrong to think being proud of someone implies at least a prior superior/subordinate relationship?