Mrs. Helena walked into the pregnancy check-room when her name was called by the clerk.
Mrs. Helena: "Hello Doc, see you again."
Dr: "Hello too, whose mother's name?"
Mrs. Helena: "Helena sir, forgot time, I've been here many times."
Dr: "I'm sorry Bu I forgot.It's a lot of patients, please go to bed and undress for me to check."
After a while, the doctor said: "Well, if this must be Mrs. Helena!"
It turns out the doctor knew Mrs. Helena not from his face.