You never know how you're going to react in certain situations.

Will I fight off a thief or run? Will I stop, drop and roll?

Will I remain hopeful and optimistic even when my doctor gives me three months to live?

I'd like to say I'd be strong enough, that I'd do the right thing. But I wilt at conflict, I tend to give in, and I cry at TV commercials.

That's what makes Randy Pausch so inspiring.

Last year the computer science professor at Carnegie Mellon was diagnosed with pancreatic cancer. His doctor gave him three to six months of good health, not much longer to live.

One month after his diagnosis, Pausch, still able to do clapping push-ups even with 10 tumors in his liver, gave to his students and colleagues the most moving lecture of our generation called "Really Achieving Your Childhood Dreams."

Pausch shared with the packed auditorium his childhood dreams and dispensed advice on how others can achieve their own career and personal goals.

His talk last September was part of the university's "Last Lecture" series where professors give a lecture as if it were their last.

And for Pausch, who died Friday at the age of 47, it really was.

It's hard not to cry when you're watching the video, now a YouTube sensation with more than 3 million hits. You know, in the back of your mind, he's dying. He admits it. In fact, his first slide shows his CAT scans.

And yet he stands there, clad in a Disney polo shirt neatly tucked into a pair of pressed khakis, smiling, laughing, gushing with passion and a zest for life.

He doesn't have much longer to live. He's leaving behind a wife, two sons and a daughter. He's only 47.

But that's not how Pausch wanted to be remembered, as a dying professor wallowing in self-pity that his life and career were unfairly cut short.

His legacy isn't pancreatic cancer. In fact, it's not even his work as a Disney Imagineer or as co-founder of the school's pioneering Entertainment Technology Center.

The purpose of his lecture was to inspire others to chase their dreams, to never give up, to be honest and grateful. He wanted to teach people how to live — not how to die.

"Never underestimate the importance of having fun," he said, smiling. "I'm dying and I'm having fun. And I'm going to keep having fun every day because there's no other way to play it."

That's not easy to do, to be so strong in the face of death, especially when it's your own.

And watching him talk, with that contagious smile, makes my problems — looming deadlines, piled-up laundry, a $300 cell phone bill — so insignificant and petty.

Here's a guy who's battling cancer, who loves this life he has for only a few more months, and he's still hopeful and passionate.

If only we could all be that brave.

To learn more visit www.cmu.edu/randyslecture.

Reach Catherine E. Toth at ctoth@honoluluadvertiser.com. Read her daily blog at blogs.honoluluadvertiser.com.