Kissing my daughter's cheek as she leaves for school each morning, I try to linger there a moment, my cheek against hers, and savor the cool softness of her youthful skin.

"You know I like to do that," I said to her one day this past week as she pulled away, eager to gather her books and belongings before heading out the door.

"I know," she replied matter-of-factly. "It's a mom thing."

"A mom thing," I thought as I stood at the narrow window by our front door, watching her board the school bus. It is the same window where I have stood for almost 20 years now, watching my children as they left for school each morning.

Standing there, remembering my daughter as she pulled away from my lingering touch, I feel the paradox of a mother's love: In loving our children, we help them achieve the independence they need to grow away from us.

And with three almost-adult children - they're 25, 21, and 16 now - I am acutely aware of how quickly children pass through our lives.

I wanted to share that thought with a young mother I saw in the grocery store recently.

The woman, with three kids in tow, had just maneuvered a loaded grocery cart into a checkout lane. One child, about 6 months old, sat in the cart facing her. Another, about 2, was in her arms, and the third, not much more than 3 years old, pranced alongside the cart, holding herself, and saying, "I have to go really bad."

The young mother, not wanting to get out of line and extend the grocery shopping ordeal any longer, pointed to the bathroom door, just steps away from the checkout line.

The little girl begged some more: "But I want you to take me."

The mother, holding the 2-year-old, bent down to whisper in her daughter's ear, instinctively touching her cheek in gentle reassurance. The mother then placed her hand firmly on the little girl's shoulder and turned her toward the bathroom door.

The daughter, buoyed by her mother's confidence, darted away. Moments later she returned to her mother's side, happy in her new-found independence of being able to handle such an important task all by herself.

I was with my own mother again this past weekend, and decades have passed since she stood at the kitchen window of my childhood home, watching me and my brothers and sister come and go to school, to work and to college, and, eventually, to lives of our own.

When I visit her now, we spend quiet moments together, as she is in a nursing home, confined to a wheelchair following a severe stroke more than two years ago.

Bending down to kiss her goodbye, I know that the effects of the stroke prevent her from following my touch, from prolonging our time together.

As I move away, though, I feel her fingers against my forearm, holding me there a moment longer, before my own life takes me away from her.