They've been on tv forever. Since little kids, showed them learning how to ride a bike, swim, play sports, all the normal things kids do. Only difference for them is one controls one side and the other controls the other side.
So think how hard it must be to do the simplest of things, like ride a bike. Their timing has to be perfectly in sync, especially for swimming.
Unfortunately complications will be inevitable for them, organs will be strained and unable to supply the demands for two. They did briefly show an X-ray of them when they were very young, and you can see skeletal remains, like the one on the right, her left arm/bones can be seen across the back, like if your arm was holding the person next to you.
The problem is they don't have double organs, so sharing the same organs will eventually overwhelm their one body. It's amazing they even survived the birth, never mind going on into their 20s. Doctors are stunned, and really have no idea of what will happen because this is such a rare case.
But just like all the other kids growing up they are incredibly Happy. The mother did say that when they were young the biggest problem was people just wanting to look at them or take pictures of them. It was very difficult to get any privacy.