When I am on a strict diet (low carb or low fat), I notice that it's hard for me to recollect things. I tend to forget the things I was thinking about a few minutes ago.

One instance was - I was going out so I knew that I need to get my sunglasses, and by the time I reached my closet (in about 20-30 seconds) I forgot what was I supposed to get.

Is this common?