I've often seen this with coding -- another reason (if you needed another) to avoid premature optimisation is, in my experience, it often specialises code to a

I've often seen this with coding -- another reason (if you needed another) to avoid premature optimisation is, in my experience, it often specialises code to a special purpose, and can make it harder to make changes later. Often a simple implementation of an algorithm can be within 10% of the performance of a much fancier one, and is much easier to adapt later to a new use. Even if the less optimal implementation is ten times slower, that still doesn't matter if it isn't on the critical path.