I often imagine what it would be like if my father were still here to mark his 100th birthday, if Alzheimer's hadn't clawed away years, possibilities, hopes. What would he think of all the commemorations and celebrations?

The memories stayed with him for so long, and stayed vivid. And it didn't matter to me that he'd already repeated that before. I could hear it forever.

There is a point in the grieving process when you can run away from memories or walk straight toward them.

Laura Bush went on national television during the week of my father's funeral and spoke out against embryonic stem cell research, pointing out that where Alzheimer's is concerned, we don't have proof that stem-cell treatment would be effective.

My father, for his part, was not a man to begrudge anyone a divergent opinion; he'd have been fine if I had written some articles disagreeing with his policies, or even given interviews, as long as I was respectful and civil.

I have a feeling of reverence about my father being in his 80s - a feeling that I want to whisper, take soft steps, not intrude too much. He's like a stately old cathedral to me now.

It's one thing to show your love for someone when everything is going fine and life is smooth. But when the 'in sickness and in health' part kicks in and sickness does enter your lives, you're tested. Your resilience is tested.