Essentially, anything that follows has to be able to make the experience of "fun" more recognizable to the reader. It has to possess a sense of exact examples and descriptions that bring to light what "fun" is. Essentially, you would be providing an operational definition of "fun," meaning what fun looks like, what is sounds like, and what elements comprise "fun." This is going to be subjective. The previous post presented a good example of this. Yet, I think for you to be able to make this your own, you might have to reflect on what elements would help to make a birthday party, "fun," and incorporate that into your statement. In the end, this is what makes abstract concepts so enticing in that individuals, any individuals, are able to construct their own attachments through their own experience in making language more concrete and able to relate better to people.
We first played pin-the-tail-on the donkey, which featured lots of absurd places for the tail (like the tip of little Fredrick's freckled nose) and plenty of squealing and belly laughs. Then, Mrs. Rose sat all twelve of us in a circle, and we played a spirited game of duck-duck-goose. And, just before the delicious Carvel ice cream cake was served, Mr. Rose read us the book "CDB" by William Steig. It was weird and hilarious. Everyone had a great time.