He didn't know the name of his home station and was not able to find his way back. Instead he was sent to a shelter, adopted and taken to Australia, destined to never see his family again. Until he sat down one day and started using Google Earth. He traced rail lines, looking for landmarks, until eventually he found what he thought might be his hometown.
If you have 20 minutes, read the full Vanity Fair piece on the story. It's worth the time. But if you'd like a condensed version, there's a three-minute video Google produced.