Wow! I think he meant:
Mom, thanks so much for getting up with me each morning while I go to this pretty hard summer job. I appreciate that since I started coming home from school for lunch, you have let me make all my own lunches and learn how to fend for myself. In fact, only making me two lunches in 3 years. This has taught me many lessons. So I realize that it is summer and you don't have to wake up early and don't have to make my lunch--I'm capable. That's why I appreciate so much your making this lunch each morning. I understand that this is your way of telling me that you are proud of my hard work. In fact, I appreciate all that you do for me....
Or perhaps, he just meant, "I like your sandwiches."
Whichever...it made my day.