procedure

So, in my past few weeks of baking, I've begun to sift my flour before adding it to the mix - I've only been making loaves I've made many times before, by the way.  I started doing it in an attempt to make my measurements more exact, but it seems that the crumb has improved since I've started to sift.  Am I only fooling myself here, or does sifting it really make a difference?  Just curious.... thanks!