It’s not much, but it makes their day. They look forward to their cookie at the first sign that lunch time is approaching.
Afterwards, they get into some serious playacting, trying to persuade us that we had, in fact, forgotten to give them their cookie five minutes before. One time in a hundred this actually works. I can only imagine the level of satisfaction this gives them. Two cookies, and fooling the man, both on the same day.
The point is, it doesn’t take much to make their day.
And I think the same is true for us.