We also live in the age of plenty in regards to how many things we have running at the same time, or how many tabs there are open in a browser. Things can add up pretty quickly.<p>And why settle for &quot;without optimizing it&#x27;s slightly faster than things used to be when people had to optimize&quot;, when you can have &quot;optimized, it&#x27;s orders of magnitude faster than things used to be&quot;?<p>&gt; you worry about efficiency once you have a lot of adoption.<p>Sometimes things can be tricky to refactor if you didn&#x27;t move carefully at every step. Initially not worrying about efficiency at all might mean having to rewrite from scratch once you do.<p>Of course, this can&#x27;t be generalized. Sometimes it really, really doesn&#x27;t matter, unless you care about craftsmanship as a value in and of itself -- taking 10-20% more time to write code that makes you happy and proud might very well make you <i>more</i> effective in the long run.