As far as I can see, animals that dream are designed to forget them as a key survivial mechanism. This clearly comes from the days when we were too stupid to distinguish them from reality. I have confidence that plenty of mammals may be able to tell them apart too, but still, advanced as we are, it seems a miracle we can remember dreams at all if this is the case. LDing is an amazing thing, but unfortionately the majority of people don't see it this way.

Possibly over time, what if people were to completely lose the ability to LD? It's unlikely, but still possible. Seeing as few people care about it it's not hard to imagine the technique may be lost. As our minds advance (or not, it's probably going the other way), the ability to remember dreams or even be conscious in them could just fade away.

Scary thought?