Before I leave, just gonna say this
Web2.0Calc has changed my life. I went from a normal kid at school to someone who loves math and dreams of a bright future (ok maybe not so much anymore because school is depressing).
I was using the online calculator one day when I was curious and clicked "forum".
I was intrigued at the type of math questions that were asked. My view on math at the time was boring and easy, as school doesn't really provide you with the best math. But seeing the math problems, I was immediately hooked and I wanted to solve them.
At first, I asked some questions, then I started answering them. Soon I was using this as my "second education", literally the amount of things I learned from here is insane.
Of course, there is AoPS, but that wouldn't have been in my life if it weren't for Web2.0Calc
This is my massive thank you to this website, it made me into a nerd, and I am grateful for that.