"Pay It Forward" for the month of November.

Not sure where to post this so forgive me if it doesn't belong here but I thought it would be an interesting topic for discussion and I am curious to hear other people's thoughts on this or if anyone else is familiar with it.

So basically this has happened twice to my husband and I this past week: We go through the Tim Hortons drive through and get to the window to be told the person in front of us has paid for our order. After the first time, I was confused and assumed the person must have drove off without their change or something. However my husband reminded me we had this happen a few years ago and his coworker told him it's a common thing for Remembrance Day - to pay for the person behind you and the idea is each person continues to do so as the line goes on. The second time this happened to us this week, we asked how much the person's order behind us was to pay for it and keep the line going but it was $17 compared to our $4 coffee order, so my husband handed the cashier a $5 bill and said put it towards that $17.

So as mentioned I was just curious if anyone has heard of this before? What are your thoughts?