reflection on good and bad

I once did a donation. What kept me thinking is that I was giving away genetical information and that women are born with a limited amount of eggs, they are predefined by birth. we loose an egg every month and it stops when the predefined number has reached its peak.
Keeping that concept in mind and transmitting it to goodness and evil I woke up today absolutely convinced that there is a limited renovable amount of goodness and evil. The Ying and the Yang.
My thought was that we all have our good and bad sides, and some people are predominantly bad. I want to believe is a minority but it makes me wonder how some of them make it to leading positions. That is scary, good and more capable people are going to yield to them to avoid being bad (or unethical, or unrespectful).
I was wondering why have we got the bad in nature, when we all have been raised to know that we should be good.
I think we are genetically conceived to be born mainly Ying or mainly Yang. That's why you can't imagine a world full of good people.
If there were too high a number of good people, the number would rebalance, by birth or a person would develop his/her mean side when a bad person would leave this world. The inheritance of Yang or its development when the numbers drop.

That for the reflection. I arrived to the conclusion there will always be mean human beings and lots of them will reach a high charge.

I wish it would work like that with happiness. If I have used up so much sadness I must have only a whole bunch of hapiness left, no?
Then... bring it on!