They will make your rediscover every little pleasure of life one by one as they grow.
They can bring so much more love to your days.
Helping them to become good persons can be your most rewarding project.
They make all workdays meaningful. After all, you have to take care of their well being.
They ground you in society, making you care about how it is handled.
They will force you to be better, as you are an example to them.
They are a mix of you and your loved one, a testament of your relationship that will outlast both of you.
They give you lots of good things to hope for as you age.
In other words, they can bring a lot of meaning to your life.
That said, I think that it is definitely not for everyone. Having kids can bring huge rewards, but at the price of a real personal investment. Like most projects, in fact.
One final reason: your kids might look like this.
This text has originally been posted on checkthis before the baby in the picture, the awesome Gilles, was born.