No, I'm not talking about my kids' reaction to something. I'm talking about NFP, actually. Someone mentioned that it's no wonder that people leave the Church or don't become Catholic, given the stance on NFP/contraception. I don't disagree with the observation, necessarily, since choosing to use NFP is a sacrifice, and that isn't all that attractive to most of us, at least not at first. I well remember my own visceral reaction when I read the Church's stance on contraception and NFP. I was already determined to convert, but I was not at all happy to read about that, or to hear that maybe I was wrong. So my first reaction was just to get angry about it and try to explain it away or rail against that particular teaching or explain how I was somehow exempt. So yes, I can understand why people leave or don't enter the Church due to this - it's a hard teaching, though I can definitely say that it's worth it. After all, anything worth something is going to be hard work and require sacrifice.
It gets a little harder, actually, because we also can't use NFP to avoid pregnancy without just reason. See this document on EWTN for more information on that. Again, the first reaction can sometimes be "but I don't wanna!". It's our natural gut reaction to want to rebel when we're told to do or not to do something. Or at least that's my initial reaction a lot of the time. As with following NFP at all, though, following it in a way that is just is also worth it. I'm reminded of the reaction when the disciples heard Jesus' teachings on marriage and divorce, actually, since they, too, thought it a difficult teaching (Matthew 19:10). But we are called to holiness, and that requires sacrifice and selflessness, which is also what NFP can help teach us.
I should add that couples don't have to follow NFP. They're free to not chart at all and leave it all up to God, and I think that's great.