Some people say that you should not micro optimize your code, but if what you love is micro optimization that’s what you should do! But you must make sure your algorithm is good before start micro optimizing.
Some might say that speed is not important but this is false. Speed is not as important as correctness, but speed does matter! If your application runs fast, much faster than needed you can add extra functionality and polish it, you can add animations or extra features. You can make it a work of art.