You can't say you know what it's like. That's like a priest saying he knows what it's like to be married. That being said I'm 20 and not sure if I want kids. I do know that although my parents have had a tough time raising me and my two younger brothers they are very proud of us now that we are coming around and making something of ourselves. I think life with just one person would get lonely. That's just me though. Even if you are one of a million I don't think you will even begin to understand what it feels like to be responsible for another life. Whether that sucks or not is not for me to decide or pass judgement.
I've taken care of people all my life, since 14 or so (at a low level then, and increasing constantly, recently come down from an incredibly high peak). I'm not married, no prospects at present. I do not particularly have any desire to have kids because I am tired of taking care of people; besides there's almost zero likelihood that I would have a child before 30. I missed a lot of life and want to have some fun for a time, preferably with a like-minded woman. Fun, for me, is defined as not constantly having to plan around another who cannot care for themself. The only real reasons I would consider kids is if I find someone special who has a child, or if we decided to adopt. Both of those options would have the full depth of my soul behind them. There are so many needy kids out there, and so many parents having 5+ kids; the disparity makes it seem heartless to have children of my 'own,' though I in no way intend that to be a criticism of others' choices.