A Carnegie Mellon University professor whose "last lecture" of his life's lessons became an Internet sensation was celebrated Monday for challenging people to strive for more than they thought they were capable of, while remembering to have fun.

About 400 colleagues and friends gathered at Carnegie Mellon to remember Randy Pausch, a professor of computer science, human-computer interaction and design, who was recognized as a pioneer of virtual reality research.

He died of cancer in July, 10 months after giving the lecture that touched millions worldwide. He was 47.

Pausch had the ability to resonate with so many people because they "instantly understood he was the real deal, a genuine hero, in an age when more conventional heroes, especially political leaders (and) sports figures, all too often, turn out to have feet of clay," said Brown University professor Andy van Dam, Pausch's mentor.

• Click here to watch 'The Last Lecture' in its entirety on YouTube.

• Click here for Randy Pausch's personal area on the Carnegie Mellon Web site.

Pausch was diagnosed with pancreatic cancer in September 2006. A year later, he gave the 76-minute speech that became the inspiration for a book "The Last Lecture," co-written with Wall Street Journal writer Jeffrey Zaslow.

Van Dam, who urged Pausch to become a teacher because of his ability to inspire and connect, called the lecture "the ultimate performance ... It gives you something meaty to think about, to process. It was done with incredible panache, flair, humor."

"You had to be sad for him, that that kind of talent and charisma and accomplishment would not survive," van Dam said. "Terribly sad, but again, terribly inspirational at the same time, that someone could do all that in the face of certain death."

In the lecture, which Pausch said was actually for his three young children, he urged the audience to "Never lose the childlike wonder. It's just too important. It's what drives us."

He said its true lesson was not "how to reach your dreams. It's about how to live your life." Live life right, he said, and karma would take care of the rest.

Stuffed Tiggers were placed on each auditorium chair as keepsakes. They were a reference to how Pausch saw himself: energetic and optimistic, as opposed to the mopey Eeyore, even when faced with certain death.

People placed dozens of stuffed animals on the stage in his memory as Pausch was fond of them, particularly winning them at carnivals.

Jesse Schell, an assistant professor of entertainment technology at the university, said Pausch constantly imparted the message: "You can do more than you think."

"In a way, I kind of think of it as Randy's philosophy in a nutshell," he said. "Thank you, Randy, for challenging me. Thank you for challenging all of us."

Ben Buchwald, one of Pausch's former research assistants, recalled how Pausch would push students to strive for their best.

Even now, he said, "I kind of have in my mind not to let Randy down."