There are so many reasons it's hard to be exhaustive.

Selfishly, nobody will love me like my children, at least in their early years. They're also amazing playmates and students. And they give me social permission to do silly things like climb on playground structures. They're also a great excuse to get out of stuff.

Selflessly, I believe me and the mother of our children are sensible people and the world needs more sensible people. Plus someone needs to maintain the replacement rate. And it's a weird, warm, fuzzy feeling to care for one's children at one's own expense.

In the intersection, it's a fun challenge to try to achieve balance in life, work, and family. I also really appreciate the chance to get a do-over of everything my parents did, keeping the good stuff and improving on the bad.