What has been the most valuable learning from summer Chemistry and why?

I decided to take away 6 weeks of my summer to take Chemistry. It has been very hard especially because all of my friends are out every night why I am sitting at home study. The good part about taking this course is that I learned a lot out of this class. First I learned and studied periodic table. Before this course i thought the periodic table was just a bunch of number and letters but I didn't understand what any. But now I understand each element, with its atomic number, and its atomic mass. I also really liked doing the unit conversion, because i understand the math. I also learned a lot about water, and water pollution, and that we have to conserve our water.