My Dad's answering machine message:
"Hello, this is Bill M's house. I'm not here. Then again I'm not all there either. So leave a message and I might get back to you if I'm ever all here."
Would have been a bit creepy, once he wad diagnosed with dementia, but his favorite joke. was, "I went to the doctors, and told him I couldn't remember. The doctor said, "What can't you remember?" And I answered, "I don't know. I forgot.'"