This highlights to me the importance of simplicity (cute kid alert!). You can't help but appreciate the simplicity of these pictures, when most folks would have been taking pictures with a cake, balloons and plenty of presents.
It also helps you appreciate the sweetness of that age. And makes me a little jealous that my parents never thought of this. Is it too late now for me to have a karate party? I promise not to pronouce it Kah-rah-tay.