Interesting detail I just realized - the somewhat shocking scene in season five where a sick Don hallucinates that he kills Andrea Rhodes (his former flame) seemed strange and out of place when I first watched it, but re watching it now it totally makes sense. Don is just reliving what he wished had happened when he was raped by the prostitute who was taking care of him when he was bed ridden as a young adult. He's just acting out a revenge fantasy in his head that he's been building up for years.

This is also interesting because it illustrates why he's always afraid of people helping him when he's sick - he distrusts any attempts to help him as an attempt to exploit him.

Just a couple of interesting things I noticed.