Simplicity

Simplicity is the principle that most systems work best if they are kept simple rather than made complex. Therefore simplicity should be a key design goal and unnecessary complexity should be avoided.

Simple is usable. Simple is complicated.

When you start looking at a problem and it seems really simple with all these solutions you don’t really understand the complexity of the problem. And your solutions are way too simplified and they don’t work. Then you get to the problem and you see it’s really complicated, and you come up with all these convoluted solutions. That’s sort of the middle and that’s where most people stop and the solutions work for a while, but the really great person will keep going and find the key, underlying principle of the problem, and come up with a solution that works.

— Steve Jobs