Raising a child is the ultimate challenge both intellectually, physically and mentally. If you don't agree it is proof that you have not raised a kid.

Beyond the normal challenges, once in a while your kids are going to do (or say) something that will just send a shiver down your spine.

Like some years back when my son, Suchet, was 3.5y old, casually told me "Pappa, I am getting bored. Let us kill Sneha (my daughter)".

Not to say, I had to double check with him what he said, and what he meant... and then explain him clearly why that was not a good idea. I knew it was just a child talk, and hence was not overly worried about it. But then I was checking on my son and daugther once in a while (every 5 minutes) after that for over a week :-).