Life is so complicated because oue emotion could be affected by many things. When you stop having feelings toward something, you will consider that you are numb. It's kinda empty when you feel numb, but it's probably the best way to make your life easier.
Sometimes, we might complain some people have low understanding ability, so you have to spend more time to explain to them. However, to look from the other side, maybe that's part of the reason why they can be a bit happier in other times. To be sensitive cannot be considered as a good thing or bad thing, because not everything can be judged with the same standard.