If you see people walking down a street and coming to a junction, it’s difficult to predict which direction they might take. But, if you see people sitting in separate boats, floating down a stream, and the stream splits into two channels, it’s likely that most, if not all, of them will be carried down one channel, the channel that has the stronger flow.
Source:
https://phys.org/news/2020-03-surfing-electrons-law.html