There are many different challenges in life, but none of them will really prepare you for the most difficult challenge you ever face that of raising children. You think it will be so easy. Everyone sees the faults that their parents had, and mistakes that they made when they were raising kids. Everyone thinks they can do better. When you actually get down to it, however, raising healthy kids is no picnic. It won't take you long to realize just how much is involved. I absolutely guarantee that you'll have more respect for your parents and the job they did by the time you're done raising a child.
First of all, raising children requires that both partners develop a shared philosophy. You don't have to get along flawlessly, but you do have to put a good face on it. You can't contradict each other in front of the kids, and you can't undermine each others' rules. When you raise children, you have to agree to always make it seem like both parents are united. Otherwise, the children will get pulled into whatever games you are playing with each other. They will try to play one parent off the other, instead of realizing the importance of respect for your rules.
Another important things that the parents have to do when raising children is to plan ahead. Having a child means a commitment of at least 18 years. You have to plan out schooling, figure out what activities to involve your kid in, plan for emergencies and things going wrong, and save up money to help them through college. You also have to plan out daily things like how to ensure that your kids eat healthy food, stay away from the wrong people, or get good grades. It can cost a huge amount of money, and it will take a lot of time. Nonetheless, the rewards are worth it.
Although it is difficult to realize the stress of raising children before you actually do it, it is nearly impossible to understand the rewards. There is nothing quite like seeing your child grow up, happy, healthy, and ready to start a bright career or future with someone they love. It really gives your life continuity, making it all seem worth the work you put into it. Once you have a kid of your own, you get a new sense of the purpose of your life. There is nothing else quite as rewarding as that.