Some things will remain hard no matter how much you practice. Usually it just doesn't feel hard anymore when you have enough experience. Being good at something doesn't mean that it's easy and everybody could do it like you do. They don't have your experience in doing so.
It might not be that easy for you either every time. That's the time when the vast experience comes into play: you can do it even if you feel like it's hard because you have all those past experiences having done something similar. There are also those just a bit harder than usual cases, just above your skill level and at the border of your comfort zone. For less experienced those tasks might seem impossible, but for you they are a way to push the definition of easy a bit further.
It is important to do both easy and hard tasks. The easy ones give you a sense of progress while the hard ones reward you with the feeling of accomplishment. If everything is easy you'll get bored and if everything is hard you end up frustrated.