Remember, always, that life is a game of chance and choices.
Even when you choose to do nothing--that's still an active choice. By choosing to do this thing or that, your life may be improved or impoverished. Choosing, for example, to spend your limited time on this planet on the Internet, playing games, participating in idle distractions...not a good choice.
The Internet is best used as a tool for education and for knowledge. It can be a lovely tool for entertainment, yeah, but it's best to keep yourself sharp.
If you're a high-schooler or in college, here:
www.khanacademy.org/Go there. This guy is a genius and he explains things in a way that anyone can understand.
There are a few short quotes I've got on my walls that help me out:
"Who dares, wins."
"Fortune favors the bold."
More than just being axioms, these are true; people who TRY are the ones who succeed. People who don't try, who give up or never start, are certain never to get any worthwhile victory.
Lots of people are saying, "Read books", but you have to consider what it is you're reading. I cannot recommend scientific works enough, but make sure that they are legitimate works of science before taking them seriously. Read ANYTHING by Carl Sagan.