@hamje32 - That’s a decent analogy but it’s not perfect. If I understand the article correctly, it’s not that voltage can’t under any circumstances flow in the reverse direction. It’s that it has to be very high to do so.
Apparently there is some threshold you have to reach for that to happen. At any rate it’s been a long time since I looked at circuit diagrams.
One thing I remember is that the symbols for the diodes used arrows to represent the direction of the current flow. Clearly you need to know which way the current is flowing if you’re going to use them effectively in your application.