I was reading Carl Sagan's book Dragons of Eden. All that's missing is the sexual link. The release of some sex-related hormone is probably essential to that process of transfer. That's what the race needs to survive. Sex and sex-related dreams are necessary to memory.
Animals propagate with just a few days in heat a year.
For reproduction, there's no need for humans to have sex and dream about sex all year round. We need year-round sexual stimulation for what it does to memory. Dad's gone now, because his short-term memory is all used up. As he lies there I don't think he sees us at all. I think he just sees images from deeply embedded memories being replayed beyond his control, racing in front of his inner vision one after the other.