12 years old, wrote my first bit of JavaScript. One of the first really great things I learned was the for loop. I think my first use was something like:

for (i=0; i<1000; i++) {
document.write(i);
}

I was incredibly excited when I realized I could get my browser to print every number from 1 to 1000. I was even more excited when I realized that if I added enough zeroes, the browser would crash and die. And so began an interesting journey into breaking stuff...

I can only hope that anyone who has the know-how to spoof their user-agent string isn't still using IE.