Yes this is part of the process. I watched my Grandmother-in-law do the same things. She became very paranoid and so forgetful. She would turn on frying pan and walk away. The porkchops were found in the linen closet. She would not come over to her own daughter's house for Christmas that year as we were all talking bout her. She also did not want to leave home as people would get in the house.
She locked the basement door as someone might be down there. Poor Grandma and Grandpa, it was very hard for him. They were married more then 65 years.
Bless you and I hope wish you all the best.