"You've got to stand for something, or you'll fall for anything."
"... as simple as possible, but no simpler."
"There's no such thing as a free lunch."
"There's no substitute for experience." (so go get some)
"Premature optimization is the root of all evil."
... why bottoms-up programming can work better than top down design (because "it gives you time and room to refine a vague specification" when "...you are programming in an exploratory way, trying to get a grasp on hardware or software or real-world phenomena you don't completely understand.").