"I realize now that as hard as I tried to understand Tiger, he tried just as hard not to let me, " he writes.

WSJ: Honoring Tiger Woods for What He Is

"The first few years, I tried to hide my disease and pushed myself as hard as I could, but there was a point when I simply let go, " said the Saratoga, California, resident.

CNN: STORY HIGHLIGHTS

So as a father of two young girls, I've tried hard to be a good dad.

WHITEHOUSE: The White House Blog: The President

As I counted the hours on my last day at Desert Rhino Camp, I tried hard to remind myself of why I was there: to learn about rhino conservation, not to tick off a sighting.

BBC: Saving rhinos in Namibia