I have a brother who was born on February 29 and we somehow manage to find a way to treat him like however many 29ths he’s had in his life, not how many years he has been with us. On his 36th birthday, but his 9th actual birth date, we took him roller skating to treat him like a 9 year old. Then we walked down Bardstown Rd to a place that played music from when he was nine. It was great fun.
This extra day every 4 years can incorporate science, history, and many other learning ideas. In the not too distant past, the Olympics, both Summer and Winter, were held only in Leap Years. It became such an expensive undertaking and logistical nightmare, that eventually, the Winter and Summer games rotated every two years. It allows people to plan on attending each bi-ennial Olympiad, rather than having to choose one or the other every 4 years because of the expense involved.