I have a 10-year old son who loves holding the door for people and I'm always somewhat surprised by how many people don't thank him. I've encouraged him to keep doing it anyway and to focus on the fact that he is doing a good thing rather than expecting acknowledgement from others. But, it's pretty sad that so many grown-ups would fail to thank a little boy who is doing something nice (without being asked!). Anyway, it was a nice thing for you to do (even if the recipients of your kindness didn't appreciate it!).