Men walking down hollywood Blvd were asked at random to say their girlfriends eye color. Several of them could not do it despite the fact that they look into their girlfriends eyes nearly every day. This is an example of how        Is not an effective encoding strategy

This might be because of the fact that when one stimulus/object is seen everyday, we get used to of it and it does not capture our attention as before. It is related to Encoding. 

One other reason could be that everyone in the circle has same eye color as that of his girlfriend. So, his girlfriend's eye color did not stand out, and he couldn't remember.