something i was thinking about

i was just thinking..
this world is full of stress suffering sadness pain sickness death etc.. i'm not saying that there's no joy and laughter and other good things.. but u can't deny that the bad things exist..
why do people want to bring life to this world (ie giving birth) then..?
answering the question, i would say i want to have kids of my own cuz i love them.. i know i will really love my children more than anything in this world.. but if so, am i thus being selfish..?
i bring my kids into this world because i love them.. but then they'll have to go through all the horrible things in life.. doesn't this mean i'm just doing it for my benefit..? and that i'm ignoring what's really good for them..? how can u call this love then..?