To try and fit reincarnation into a neat mental package is very unwise. You will be very surprised when you discover that it doesn't work out that way. Your illusions will be painful for you.
If you wake up for a moment and look around at life, you will observe that nothing here lasts, nothing works out. There are no happy endings. All accomplishments are washed away by death or by the next moment.
Karma doesn't mean that everything works out justly.
Sometimes in an incarnation you get a feeling of frustration. It is not working out the way you want. If you pull your power together and meditate, no matter what happens to you physically, you will have gained from this life.
You human beings think that yoga is in some way going to make everything you want to happen, work out. You are going to be able to avoid what you don't want. That is not yoga. That is desire and aversion.
