I dislike the way the "premature optimisation.." quote is misused, and quoted without the benefit of its original context.
I take the quote to have 2 meanings:
- Get the code working first then worry about optimising.
- Don't rush into optimisation without profiling the code first.
The benefit of #1 is that you can keep your working, reference implementation and ensure the output of your optimised version is still working correctly. And #2 gives you the best bang for buck, since as developers, our time is precious.