<human>: Can you summarize the given text in a few sentences?

Completely out of the blue my d-bag brain of mine started bringing up memories of my childhood. One specifically that came to mind has made feel unreasonably guilty. I figured this would be the most appropriate place to get it off my chest.  

I was maybe 10 y/o at my house during summer break. My parents were away at work, and I had the place to myself. For whatever reason, like all kids, I had a huge random craving for pizza and was determined to get some delivered. Being 10, my income was rather low, but I knew that I had a TON of spare change saved up. So I called up Tiffanys (the best local chain pizza in southeast MI), ordered some delivery and got my total price. I proceeded to count out the EXACT change, and when the delivery man came I clumsily dumped two hand-fulls of coins into his hands. Also being 10 I had absolutely no proper concept of how tips worked. 

I remember him giving me the most frustrated/puzzled face and then counted and recounted the coins for what seemed like a good 10 minutes. When he confirmed it was right, I said Thank You! as excitedly as any kid would and shut the door. 

Now that i'm an adult and personally know many friends who are servers and delivery guys/gals, I can understand how infuriating getting stiffed for a tip can be, especially by punk kids. He practically delivered the pizza to me for free. IM SORRY PIZZA DELIVERY MAN. I DIDNT KNOW ANY BETTER.
<bot>: As a kid I ordered delivery, paid in all change, didn't tip, pissed off the delivery guy, now feel guilty remembering about it.