The big mistake many people make is:
- thinking in advance about future lives
- thinking that destiny is not changable
- or thinking in advance about after-life

The latter is typical to many religions, particularly those most popular ones.

First, future lives may never happen, may be irrelevant and unnecessery.
Second, there is power within which may choose (alter) a certain time-line.
Third, thinking of after life makes no sense when being in physical.

Does it make much difference whether you would incarnate 5 times living for 100 years, or live just once for 500 years?