Everyone is unique. The human genome allows for much more number of humans to exist than ever existed and will exist. Every human's genes are different, even if slightly because until recently humans bred within their own groups and races, and their is no enough diversification although it's allowed by the genome.

Every human's experiences are different. And thus different humans are different, if not by the experience, its by their genes. Can you have two Issac Newtons, or two Mozarts? You can find Albert Einstein and Beethoven, but they are't the same as Issac Newton and Mozart.

Said that, I think different experiences and different genes ultimately generate the same emotions. Here I think you are right, we are all the same. But this is a good thing, because this means we can sympathize and empathize with others, because we understand how it feels to be, say, lonely. But how we express it could be different.