Life's tough, but it's tougher if you're stupid

With still more baffling displays of idiocy my dad and stepmom are very close to driving me completely insane!
Dad called me yesterday, then forgot who he had called when I answered and said "Oh, hey, I was wondering who I had phoned!"... He then proceeded to tell me that my sister was coming to town, and told me where from - like I just happened to forget where she lived?? A frustrating phone call at best.
Then I called them today, from Deanna's place, around 3 o'clock to see if my sister was in town yet, because my dad said she was coming straight there when she arrived... My stepmom said "No, her haircut isn't until 5" "Yeah, but Dad said she was coming there first" "No, I don't think she'll be here until around 6:30 or 7" "Hmm, do you have her cell number? I don't have my adress book with me" "Oh, your dad is beeping in... ... ... ... Ok, what were we talking about?" "Erin" "Oh, right. She's not here" "Could you tell me her cell number so I can call her to find out what's up?" "Why?" "Well, to see when we're going to go visit Grandpa in the hospital and to see what she's doing tonight and all that stuff" "Why don't I just tell her to call you when she gets here?" "That will be too late for if she's visiting the hospital this afternoon. Can I have her cell number?" "She can phone you when she gets here. I can write down the number off the phone" "Um, no, I won't be here in 4 hours. Can you just tell me her cell number so I don't have to go home and get my adress book?" "Why won't you be there?" "Deanna is going to work at 5" "Oh, so you'll be leaving soon then?" "Yes. So can I just have her cell number so that I can reach her soon?" "I guess that might work. Let me find the adress book.... ... ... ... ... 5 minutes pass... ... ... Ok, here it is: ___ -____. Will you be calling her?" "Yes, now Deanna needs her phone. Thank you."
I called back a few minutes ago to see if my sister was still at their place and my dad actually had to THINK about it before he said "Yes"!!!
This is nearing the idocy displayed the time he told someone they had the wrong number because they asked for 'Lindsay' instead of 'Fred'...
WHAT'S WRONG WITH THESE PEOPLE???

I shall just play fowlwords (my new addicton) to relieve my stress.