Blessed... at Meijer

Just wanted to bless you ma'am, that's all. 
Every time I asked why, or if he was part of an organization or youth group or something like that, he just kept repeating the same thing.
Tonight, I had to run out to pick up ginger and some more cheese for tomorrow.  Things I kept meaning to get earlier in the week, but kept forgetting about when I'd actually get to the store.  Just a few things to finish up the cheese and crackers for before the meal, and pie for after the meal tomorrow with my family.  Of course, once I started walking around the store, I couldn't just stop at just cheese and ginger.  I also had to pick up some summer sausage since it seemed like it'd go well with the cheese, and there were those Christmas peanut M&M's Tim had his eye on earlier in the week that I thought I'd surprise him with.  And of course under the guise of needing it for baby J to try, I picked up an avocado fully expecting to be able to finish the rest tonight after he went to bed [don't want it to go bad after all ;) ].  Then there was the milk, only one gallon, but still necessary since we finished our other one up earlier today.
After finally deciding I should head home to prepare things for tomorrow, and so I could get little boy to bed soon, I headed to the self checkout line.  I only had a few items, so it wouldn't be too bad.  There were a few lanes open but they weren't to easy to get to with the big cart.  I had to go around the center divider thing to be able to get to the one on the end.  The store was busy!  As I headed toward the checkout lanes, I saw two younger people, a boy and a girl, probably high school aged, just standing there.  They looked like maybe they were waiting for someone, not inline to check out [especially since there wasn't a line].  I didn't give it much more thought than that.
I started ringing my things up.  Lots of cheese, but it was having problems scanning.  The cashier came by and remarked how cute J was... I agreed while still trying to ring up that cheese.  Finally the cheese was in the bag along with the sausage.  I reached for the sweetened condensed milk and heard behind me, Ma'am, can I pay for your groceries?
There was the high school aged boy standing behind me with a wad of cash in his hand.  I was speechless... and then agreed, not really knowing what else to do.  I rang up the rest of the things, meanwhile the girl came up and handed him more cash.  Apparently my bill was a little more than what they expected.  I wanted to step in and say they didn't have to pay for it all.  I wanted to say that they should wait for someone else who was more needy.  Surely there was someone else in the crowded store who needed it more.  I don't know why they chose me.  Was it because I was alone and with J?  Was it because I only had a few things?  Were they standing behind before waiting to find the person they would choose to pay for their bill?  I don't know.  And I'm not sure I want to know or think about those things too much.  But as I put the bags in the cart and headed out, I saw the two kids with adults, presumably their parents and all I could do was smile.  I had said thank you so many times as he put his cash into the machine, but really how many times is enough?  I wish I could go back and talk with them.  I was embarrassed and didn't really know how to react, but very thankful at the same time.
I want to do this same thing some day.  Maybe make it a tradition with my own kids?  Just this one act had such an impact on me today, and it would be nice to pass it on to others... Just want to bless you ma'am, that's all.