Karma?

Last week I was running super late and needed to run into the store to pick up some flowers and a Starbucks gift card for Jasper's Kindergarten teacher.
I run in with Tindra (Jasper was still in school) and grab my things and get in line.
In front of me was a young man with a huge cart full of groceries. The cashier said something like "Looks like you are pretty hungry!" and he replied "It's not for me but there are two hungry families waiting for this" 
After about 2/3 of his groceries have been rung up and he sees the total he tells the cashier to stop, that he won't be able to get the rest. The total was something like 150 and there were still a lot of groceries left. He pays for the groceries and starts to leave. 
I had noticed that he had bought 5-6 containers of lunch meat, but the bread was still left behind so without thinking about it I told the cashier to ring up the bread and watermelon with my stuff. I mean, what good is a bunch of lunch meat going to do if they don't have any bread to eat it on. 
She said "Are you sure?" and when I nodded "Let me run out and grab him!" and left to yell out the door to come back as I paid for my items.
The man was very humble and grateful. I wasn't sure How he was going to react. Some could take it the wrong way or get offended if given food when they haven't asked, but I didn't think about how he was going to react just did it so honestly I was a little nervous that he was going to be pissed or offended. Luckily he was neither!
The best part of it was the guy behind me in line quietly offered to buy the boxes of cereal still sitting there, with the un paid for pile of food. So on top of the bread and watermelon, he got to take the 3 boxes of lucky charms sitting there as well. 
The cashier looked more surprised/happy then anyone and told me as I was leaving that I just made her day. But you know what? It made My day to do it. I felt grateful that this small opportunity to do something good for a stranger presented itself. It feels Good to do good, right? 
 I wish I could have done more, but all I had was cash on me and not very much, but I'm still I was able to do something for this young man who was buying groceries to two families in need. I don't know if they were his families, or friends, or complete strangers, but that's not the point. The point was, someone got a sandwich and watermelon for lunch that maybe otherwise wouldn't have. 
Oh and the silver lining (not really) of it all? I walked out to a freaking $50 parking ticket. Apparently it was the monthly street sweeping day and my good dead for the day had made my grocery trip 5-6 extra minutes that probably would have saved me from a ticket. What kind of karma is that?