How many people are you in one day? You get up in the morning and you're a mother/father at breakfast as you get the kids to school. You become a commuter as you travel to work, then when you get there you become a colleague. Still the same you, but variations on a theme. Same with reincarnation. The Soul is the 'you', and when you become incarnate you wear a certain hat depending on the Life you are in at that time. In the next incarnation, you're still the same basic 'you', only in different circumstances and wearing a different hat.