Pop's version of a Knock, Knock joke

Today was Pop's 96th birthday. Yep, 96 years old! Amazing!!! He was surprised every time I wished him Happy Birthday. He asked Mom, "how old am I today?" Mom just scowled at him.

As birthday tradition dictates, we went to IHOP for dinner.

When we entered the restaurant, Pop asked, "do you know what IHOP stands for?" He answered the question himself, "International House of Pancakes."

After we ordered, Pop asked again, "do you know what IHOP stands for?" He quickly responded, "International House of Pancakes."

When our meal was served, Pop queried us again, "do you know what IHOP stands for?" as if he had just thought of the question.  Of course, he knew the answer, "International House of Pancakes."

We left the restaurant thinking the rigorous questioning was over but Pop had one more question for us, "do you know what IHOP stands for?" "I'm a Happy Old Person!"