My mom was a senior manager at a global stem-cell bank when she retired. While my brother and I were growing up, she worked part-time. I’ve heard her say more than once: “If I had just had another 16 years, I could have gone so high.”

Am I being selfish if I don’t have children?

I’m selfish for not committing to my hypothetical child’s well-being. But I will have a lot more attention and money to shower on real-life nieces, nephews, mentees and philanthropic causes.

Also, not having a child is the most important thing I could do to reduce my carbon footprint, according to a 2009 study by Oregon State University statisticians. (Of course, like all parents, I believe my theoretical child would have grown up to become a brilliant physicist and saved the world from global warming, so this is a moot point.)