As a balding tenure-track professor, he still sported a child-like grin in the lab. He spent most of his time in his small office, among piles and piles of littered paper, reading, thinking and every once in a while, jumping out into the lab area and proclaiming another breakthrough in his thinking. Sometimes I wondered whether he could have come this far if his American family had not supported his early wanderings, or if he had been raised in China, being constantly put down and laughed at as a vagabond.

However, Donald's positive attitude did not get him to the top. He chose an exciting yet extremely risky research topic. After six years, he did not find any major breakthrough and thus did not get a tenure.

I left graduate school before he did. Donald did not try to convince me to stay. Unlike the other professors in our department, he had never frowned upon my taking French or psychology classes. He must have sensed that in some way I was following in his footsteps.

I wandered - worked in biotech company, moved around the United States, went into business, moved back to China to take up filmmaking. Every time I made a change, my Chinese friends would put me down, while my American friends cheered me on. Some days I felt lost and worthless, and on others ecstatic at being able to do what I loved.

Now, many years later, I am back in business, older, calmer and happier. A week ago, I searched online, looking for Donald's whereabouts. Apparently he had started a biotech company that appeared somewhat successful.

Still, what a pity that Donald did not become an academic star, for all his intelligence and hard work, I thought.

Then I remembered his child-like grin. I knew regardless of how others felt about his path, he had been enjoying what he did, all along. It was then that I realized what Donald had taught me. Encouragement and positive attitude do not beget success; rather, they allow us to try things that appeal to our hearts, which, ultimately, make us happy.