"Have strong opinions, but hold them weakly." - If you can't consider new things and change what you believe, you only need a spinal cord. A brain would be wasted.
"Always remember who you are in the dark." - Because integrity's about the only thing that's truly yours, and is not worth discarding for a short-term gain.
"Never pick a fight you can't run away from." - Because, let's face it, most of us are fairly nerdy types who don't really want to get into fights in the first place, no matter how tough we pretend to be online.
"And this, too, shall pass." - A reminder to remember that when things are good, they won't always be this good, so enjoy them. When things are bad, they won't always be this bad, so look to tomorrow. But mostly, you'll be a long time dead and there's a lot of living to do between now and then, so don't worry about the small stuff. Because it's probably all small stuff.