When I walk downstairs, I touch the handrail on my right as I go. It's not a conscious thought, just a place to grab and steady myself as I take a first step. Neither my grip nor the weight of my hand is strong, and my palm is against the wood for only a second. But after six-and-a-half years, there's a faint yet noticeable spot of wear on the railing from my regular touches. A few inches of dark cherry stain is beginning to rub away, revealing the lighter oak underneath. It's indelible proof of a habit I didn't realize I had, because it had become so routine.  I am here. As a woman, as a mom, I often feel invisible. Clean laundry magically appears in the basket, sinks mysteriously become wiped spotless, permission slips miraculously show up signed and tucked into folders. Little thought is given, even by me, to the things I touch every day.  I recently noticed this mark on the railing and wondered where it had come from, then realized it's me - it's evidence of...