Again, an analogy would help. Just imagine a situaiton of two people reading the same book. Both have not started at the same time. Say, there is a difference of 10 minutes. And, they both read at the same speed. In this case, both will get the experience fo reading the whole same book. But just that, at different time lines (first guy - 10 minutes earlier).
Similarly we might also be experiencing same life! Not just the life of humans, but also from the very very begining. We might have lived the life of amoeba, fish, birds, dinosaurs, .... human0, human1, ..., i, ... , you ,...? Feeling this possibility is awesome!