Oddbean new post about login | logout (I'm aware that I probably dream every night but I'm not able to remember it every night, please spare me the ackshuallies, this isn't reddit lol)
Ackshually, not only is it simply because you do you not remember, but the nightmares are your subconscious still making mountains out of mole hills. The increased stress in your life is causing these things to happen.
In psychoanalysis nightmares are punitive dreams, usually negative feelings dressed with daily memories.
Do you keep a dream journal? Writing them down immediately after waking up helps us remember that we had them.