People born on February 29th only have one real birthday once in every four years. I feel sorry for kids born on leap day.
Of course they can still celebrate their birthdays every year even if not on their true birthdays. Lots of kids have parties on the weekends nearest their birthdays instead of on the exact days, but it must still be hard for children not to have their parents and grandparents treat them specially on the anniversaries of the day they were born.
Leap year and leap day only show on calendars every four years and are not natural events like years, seasons, and days. Like weeks and hours, they only exist because people agree that they do. Months and years are based on the seasons and lunar cycles, but humans have agreed on modifications over the years because the actual ones don't coincide exactly with our concepts.
So let's agree that anyone we know who was born on leap day deserves extra special treatment this year.