As far as the rest of my comment - watch the videos that I linked.
After V1 you must be able to take off on only the remaining engines. If that's not possible you must reduce weight until it is possible or you're not allowed to start takeoff at all.
This is why in very warm weather and higher altitude airports (lower performance) sometimes cargo/luggage or even some passengers are left behind, while in colder weather all seats could be used.