Although this post is short, the basic building block of reincarnation that it discusses can be one of the most difficult to grasp.
Even though you may already believe in the theory of reincarnation, perhaps you haven't really thought through the mechanics of it.
As explained in my previous post, each of us is responsible for the lessons we learn in any given life. What we learn isn't decided by the hand of some divine being or god, we learn lessons that we set for ourselves. This is a major stumbling block for some, as they don't want to take responsibility for their circumstances - it's much easier to blame it on God, or Fate or some other factor. In fact, it's very common (in the Christian world at least) when someone is beset with a tragedy, for others to offer such comforting words as, "God works in mysterious ways", or "Someday we'll understand", or "What doesn't kill us makes us stronger". While I'm sure such sentiments are well meant, they are in fact, quite mistaken. The bottom line is, you are making your own reality exactly as you planned to prior to assuming your earthly persona.
Before you entered your current life, you thought through all of the experiences you had in other lives. You created a plan based on what you wish to encounter in your current physical form, including both the pleasant and unpleasant, and any abilities or disabilities you possess. You have a circle, or cell of beings that you have been reincarnating with for many lives and you discussed the details of your current plan with them prior to taking your current form. Together you decided how best to achieve not only your own plan, but each of theirs as well. You sorted out beforehand who would be the parents, the siblings, the friends, the enemies, and even the passers by in this incarnation. Individually, you all have goals to attain, collectively you get it done.
There is a plan and you are the author.