What is admirable about ‘them’, but is too socially unacceptable/awkward to say in person?
I cannot believe that you stayed up until five in the morning just to teach some knowledge-hungry kids about theoretical computer science! That is the kind of selflessness that changes a persons life, and I wish more people were as willing to share their passions/talents with others.
After the Sandy Hook shootings, one of my teachers expressed something to the effect that she would die for us and believed most teachers are the same. That meant a lot to me and really cemented my belief in the greatness of teachers, but I figured I would sound completely deranged if I told her that.