I don't understand English jokes. Can you explain it to me? ~~

Son: Dad, I'm hungry. Dad, I'm hungry.

Dad: Hi, I'm hungry. I'm dad. Hello, hungry, it's dad. Dad knows I'm hungry because I'm hungry, too. )

Son: Dad, I'm serious. Dad, I'm serious.

Dad: No, you are hungry. No, you are hungry. Dad knows I'm serious, because I'm serious.

Son: You're kidding. You're kidding.

Dad: No, I'm dad. No, I'm dad. Dad interprets you as joking as: you are joking.

In other words, the father understands words such as hunger, seriousness and joking that his son said as names.