how could they?

i was just wondering..
1. how could a mother abuse her own children after 9 months of pregnancy journey?
2. how could a pedophile become a pedophile?
3. how could a grandfather rape their own granddaughters?
4. how could a mother leave her own child at a stranger's doorstep?
5. how could a mother be pregnant just to have her daughter's organ?
i don't understand how these things could happen.
are they stupid, insane, sick in the head or all of it?
oh well, i've been watching tv a lot nowadays.
hissshhhh! geramnyaaaaa kat orang orang gila ni!
i hope these people rot to death in prison.