I'm 42. Since I was a small girl I have always said "I don't want kids." I have been told for 42 years "Oh, you'll change your mind."
42 year. Not once have I had any urge to have kids. Not. Once.
I'm not going to say "Oh, all kids are horrible monsters!" or "Society wouldn't allow me to raise my kid how I'd want to." or "Bad genes in the family." or any of the many many valid reasons and/or excuses that people use.
I don't want kids because I don't want kids. I have no urge to bear children, to have children, to hold babies, to have the continued generation. I know great parents and great kids, and bad parents and bad kids. I don't think that other people should or should not have kids, that's their own decisions. I see a lot of people having kids that I personally think shouldn't... but that's my personal opinion.
It's not abnormal to not want kids... any more than it's abnormal to not want a partner. It is entirely possible to live a full and happy life without a partner, without kids, or without pets or electronics or all these things that most people believe are "needed". It's all in what you YOURSELF wish to put into your life. Choice.