Comment by philippta

I recently heard a great analogy for this exact problem under the premise of "Make it work, make it right, make it fast".

Assume a sorting algorithm as a metaphor for your whole program.

You make it work by implementing the simplest thing you know how to write: bubble sort. Works.

At the end you notice it's way too slow and replace with something much better: quicksort.

Now, how much of your program is surviving? Almost nothing, perhaps except for the "greater than" comparison.

If you apply that idea to a real world program, we're pretty much talking about a full rewrite.