"It can be expensive to use the wrong abstractions, therefore you should copy and paste" is not sound reasoning. The _right_ abstractions can be incredibly (in

"It can be expensive to use the wrong abstractions, therefore you should copy and paste" is not sound reasoning. The _right_ abstractions can be incredibly (insanely, ridiculously) beneficial to a code base across all dimensions -- correctness, maintainability, performance. Searching for the right abstractions is definitely worthwhile - even if it sometimes incurs extra rewrite/refactor churn. The better the abstractions used, the easier the refactoring, the faster you find the good abstractions, the easier it is to change the code as your understanding of the problem grows ...