This is kind of how I've felt all my life, I never wanted to have kids. I've lived by myself since I was 17 and have become selfish with very few responsibilities and a pretty nice life.
However, I recently learned that my GF is pregnant. We decided to have it, so I'm giving it my all to embrace this new stage of my life with a positive attitude and kind of leave all those ideas behind and to change the expectations about the life I thought I'd have.
We're 5 months pregnant at this point and I have made great progress in terms of how I feel and not having any resentment or regret. Part of me is excited and I've been very supportive and involved and our families and friends have been as well and that makes a big difference to me.
We're both in our 30s and I make a decent living, so money is not a big issue, although I did have to make some adjustments like cancel the sports package, the maid and stuff like that but nothing major and it's only for a few months.
Anyways, I do agree to some extent to what TS said, however, it's up to you how you choose to approach life with or without kids. I believe that each and everyone of us has the ability to be happy, regardless or income, marital status, job or any other circumstance. We can all be happy, today, as is. So, yeah, having kids comes with all that, but it will also give you other experiences that otherwise you wouldn't get to enjoy. So even with those nuisances, you can live a full, happy life.