My daughter Elizabeth recently stopped sucking on her middle two fingers. It was a habit she adopted within two days of her birth and has served her well in times of need, stress or boredom. As a mother to three children, I was grateful she had this self-soothing technique because it gave her comfort at times when my arms were full. About three weeks ago, the fingers left her mouth and any attempt by me to reinstate her beloved habit has been met with a blank stare as though any muscle memory she may have had that led her to suck her fingers had been erased. And the need it fulfilled? Well, that duty has now been transferred back to me.