Management, business, leadership and investing quotes and many other famous quotes

Costs do not exist to be calculated. Costs exist to be reduced.
Premature optimization is the root of all evil (or at least most of it) in programming.
If you're not stubborn, you'll give up on experiments too soon. And if you're not flexible, you'll pound your head against the wall and you won't see a different solution to a problem you're trying to solve.