Another idea from Ur-a-Jew:
Last night, a slightly different elaboration occurred to me. But before we go there, I would be remiss if I didn't quote Reb Dov (the GYE Maggid):
"Quit the thinking and figuring, ok? Consider just doing your own work. We cannot thinkourselves into right living - we can only live ourselves into right thinking."
Now back to your question. Your question assumes you're entitled to know the answer. But in reality, neither you, me or anyone else are entitled to know the how and why's of Hashem's doing. Hashem created this world in His infinite wisdom, and He put us here in His will. It is obvious that He has a master plan. And it is obvious that he is a Meitiv (giver). You needn't look further than your own body to see this. Hashem didn't have to create you with an efficient body, He did so because he is a meitiv. With that in mind, you can now try to see if there is a way to understand. (See the Sefer Hachinuch for a similar concept regarding the Taamei Hamtizvos).
I once saw a story about a person who was born without hands. Everyone felt sorry for the baby. Imagine having to go through life without hands. An unthinkable thing. Such a young cherubic looking baby. What could justify such a punishment? He certainly never did anything wrong. Cruel joke by his Creator?
Well, perhaps if we had a videotape up in shomayim we would have seen the following taking place, prior to that neshoma coming down. Reb Yid was niftar. He was a holy man who learned and did mitzvos all his life. He came before the bais din shel maaleh and it was determined that he deserved gan eden. They were about to seal Reb Yid's din when a maalach came and said, "what about the money that he once took, that was not his?" Reb Yid shuddered. It all came back to him; that incident, when he was a young teenager. He took money that wasn't his and he never returned it. In shomayim there was a big tumult. They could not send Reb Yid to gehennim. His whole life was filed with kedusha, Torah and Mitzvos. But gan eden wouldn't take him, he had gezel on his hands. So in shomayim they paskened to send him back to this world to be misakain his neshoma for that theft. Reb Yid was devastated. But he saw he had no choice. He then turned to the bais din she'll maaleh and said, "I beg you, if I have to go back, please grant me one request. I am worried that I may be nichsol again in this sin, please, if I have to go back let it be ... without hands, so I never take something that doesn't belong to me.
The Bais Din Shel Maaleh granted his request with reluctance, but they understood. It was Reb Yid's neshoma that resides in the body of the beautiful but handless baby that was born.
Now, once we're in shomayim, let's look at what else is going on.
In a different corner, there is a different neshoma. We will call him Reb FY ("FightingYid"). He is actually in Gan Eden on a pretty lofty level too. But he notices that there is a blinding light that comes from a neshama much higher up in Gan Eden. Reb FY's neshoma pined to be like that neshoma who is so close to the shechina. He makes some inquiries and is told that this light comes from the neshoma of Yosef Hatzaddik, for having withstood the tremendous nisayon of Potiphar. Yosef was hounded day and night by one of the most beautiful woman in the world. It was so easy to succumb. He was all alone in isolation, in a land where no one knew him. He would probably never see his family again. He wanted to give in, but he withstood the nisayon. Reb FY begs to be like that neshoma. The Bais Din Shel Maaleh explains that there is no way to do that upstairs. Reb FY begs and begs, and the decision is made that he will be permitted to come back to this world to try and obtain this achievement. The risks are explained to him. But Reb FY can't resist the opportunity to obtain such a spiritual elevation. So Reb FY comes down to this world (at his request) with a strong, burning desire for women, in order for his neshoma to obtain the kedusha that the it saw in gan eden.
Did this really happen? I don't know. The one thing I do know is that you are here, pursuant to a Master plan. And that the Maker of that Master plan is merciful, patient and loves us more than we can imagine.
So you have a lot of work to do. We all do. Don't miss the opportunity.
Hatzlocha.