What are you Words of Wisdom?

Curious what favorite quotes folks around here live by, often think about, or repeat to themselves on a daily basis.

Even if it's only "a favorite", what are yours?

I've amassed a few on my user profile here, and I always keep a ~/quotes.txt on my machines (though I'm not quite organized enough to periodically sync them to a central place).

I'll appreciate any indulgence you afford me and gems you share :)

Thank you!