#1. It brings out the "child within"
#2. The rides are for everyone
Most of the rides are designed for families. There are no rides specifically made for only the little ones. No matter how old you are, you will enjoy the roller coasters, the Disney-themed rides, even the slow moving rides. All of the rides can be ridden, no matter how old you are.
#3. The characters will interact with you, even if you are not a child.
#4. They have things to do other than the theme parks
#5. The dining experiences
#6. The firework shows
Each park (except Animal Kingdom) has their own unique fireworks spectacular that cannot be missed. No matter how old you are, these fireworks will blow you away.