So many people who one has helped at a point in time would somehow forget the help one has done for them, buy somehow not the best. We have people of different thoughts. The way they think towards people are not just the same.
The one you have helped today and think of remembering you in the future is the best one so far. The kind of people we have nowadays wouldn't want to remember the help you have done despite the fact that you were no expecting anything from them.
Appreciation is the best answer to success. This girl in question is the type who is destined to succeed in life and nothing cam change this fact.