Decades ago, a Detroit-based guy named Rodriguez, calling himself Sugar Man, wrote songs and sang like Bob Dylan. I especially like his song I Wonder.
Rodriguez never really made it in the music business. His two albums barely sold in the competitive US market.
Meanwhile - unbeknownst to Rodriguez - in South Africa, near the end of apartheid, his songs became wildly popular as anthems for the freedom from government oppression both white and black people craved.
The government helped by banning the songs from the radio. Then everyone had to listen to them.
Word spread in South Africa that Sugar Man had died on stage after setting himself on fire.
The image of that ending propelled more sales. A South African man spent huge amounts of time trying to obtain the details of the rise and fall of Sugar Man.
After many months of effort, decades after the reported suicide, he found that Rodriguez was still alive and cleaning houses in Detroit.
Almost no one in South Africa believed the man.
Rodriguez turned out to be an unusually nice person, who still knew how to sing and play his guitar.
The man talked with Rodriguez, who was astounded to learn how popular he was in South Africa.
The man invited Rodriguez to come and perform.
Rodriguez went and played a series of concerts to huge crowds. He was finally a star - in another land, where his songs helped usher in the start of democracy and freedom.
I tell you this story, from the documentary Searching for Sugar Man, to make a simple point: we cannot always tell what positive impacts we have on others.
The effects may be much delayed. The effects may never be clear.
I think about the possibility of positive impacts when I write for newspapers and when I interact with others. I may not be another Sugar Man, but I may have positive effects here and there.
If we keep that potential in mind, we may have greater positive impacts.
The impact might be from a kind word or a good deed at the right time or from something of value we create - a child for instance.
We may never know the impact we have. We may never perform in front of adoring fans. But we may be able to look back and think, I did my best, under the circumstances, to have a positive impact.
John Malouff is an Associate Professor at the School of Psychology, University of New England.