Suppose at some point of your universe you have some event the consequences of which you don't like. You'd like to roll it back. Due to the speed limit, said r

Suppose at some point of your universe you have some event the consequences of which you don't like. You'd like to roll it back. Due to the speed limit, said rollback affects only a limited area of the Universe. The "people" inside this area won't feel anything unusual during the operation, b/c their memory will be rolled back, too. You also need reversible physical laws for that to be feasible :)